diff --git a/pkg/server/manager.go b/pkg/server/manager.go
index 3fe739b..11a55c1 100644
--- a/pkg/server/manager.go
+++ b/pkg/server/manager.go
@@ -369,9 +369,8 @@ func (sm *serverManager) ServeWithGracefulShutdown() error {
 type serverInstance struct {
 	cfg            Config
 	gracefulServer *gracefulServer
-	certFile       string // Path to certificate file (may be temporary for self-signed)
-	keyFile        string // Path to key file (may be temporary for self-signed)
-	tempCertDir    string // Path to temporary certificate directory (for cleanup)
+	certFile       string // Path to certificate file (may be persistent for self-signed)
+	keyFile        string // Path to key file (may be persistent for self-signed)
 	mu             sync.RWMutex
 	running        bool
 	serverErr      chan error
@@ -416,7 +415,7 @@ func newInstance(cfg Config) (*serverInstance, error) {
 	handler = middleware.PanicRecovery(handler)
 
 	// Configure TLS if any TLS option is enabled
-	tlsConfig, certFile, keyFile, tempCertDir, err := configureTLS(cfg)
+	tlsConfig, certFile, keyFile, err := configureTLS(cfg)
 	if err != nil {
 		return nil, fmt.Errorf("failed to configure TLS: %w", err)
 	}
@@ -441,7 +440,6 @@ func newInstance(cfg Config) (*serverInstance, error) {
 		gracefulServer: gracefulSrv,
 		certFile:       certFile,
 		keyFile:        keyFile,
-		tempCertDir:    tempCertDir,
 		serverErr:      make(chan error, 1),
 	}, nil
 }
@@ -535,20 +533,6 @@ func (s *serverInstance) Stop(ctx context.Context) error {
 	if err == nil {
 		s.running = false
 	}
-
-	// Clean up temporary certificate directory if it exists
-	if s.tempCertDir != "" {
-		if cleanupErr := os.RemoveAll(s.tempCertDir); cleanupErr != nil {
-			logger.Error("Failed to clean up temporary certificate directory '%s': %v", s.tempCertDir, cleanupErr)
-			// Don't override the shutdown error with cleanup error
-			if err == nil {
-				err = fmt.Errorf("failed to clean up temporary certificates: %w", cleanupErr)
-			}
-		} else {
-			logger.Info("Cleaned up temporary certificate directory for server '%s'", s.cfg.Name)
-		}
-	}
-
 	return err
 }
 
diff --git a/pkg/server/manager_test.go b/pkg/server/manager_test.go
index fe8d7c1..b9785a9 100644
--- a/pkg/server/manager_test.go
+++ b/pkg/server/manager_test.go
@@ -7,6 +7,7 @@ import (
 	"net"
 	"net/http"
 	"os"
+	"path/filepath"
 	"sync"
 	"testing"
 	"time"
@@ -328,41 +329,70 @@ func TestShutdownCallbacks(t *testing.T) {
 	assert.True(t, executed, "Shutdown callback should have been executed")
 }
 
-func TestSelfSignedSSLCleanup(t *testing.T) {
+func TestSelfSignedSSLCertificateReuse(t *testing.T) {
 	logger.Init(true)
-	sm := NewManager()
-
-	testPort := getFreePort(t)
-	instance, err := sm.Add(Config{
-		Name:           "SSLTestServer",
-		Host:           "localhost",
-		Port:           testPort,
+	
+	// Get cert directory to verify file creation
+	certDir, err := getCertDirectory()
+	require.NoError(t, err)
+	
+	host := "localhost"
+	certFile := filepath.Join(certDir, fmt.Sprintf("%s-cert.pem", host))
+	keyFile := filepath.Join(certDir, fmt.Sprintf("%s-key.pem", host))
+	
+	// Clean up any existing cert files from previous tests
+	os.Remove(certFile)
+	os.Remove(keyFile)
+	
+	// First server creation - should generate new certificates
+	sm1 := NewManager()
+	testPort1 := getFreePort(t)
+	_, err = sm1.Add(Config{
+		Name:           "SSLTestServer1",
+		Host:           host,
+		Port:           testPort1,
 		Handler:        http.NewServeMux(),
 		SelfSignedSSL:  true,
 		ShutdownTimeout: 5 * time.Second,
 	})
 	require.NoError(t, err)
-
-	// Get the serverInstance to access the tempCertDir
-	si, ok := instance.(*serverInstance)
-	require.True(t, ok, "instance should be of type *serverInstance")
-	require.NotEmpty(t, si.tempCertDir, "temporary certificate directory should be set")
-
-	// Verify the temp directory exists
-	_, err = os.Stat(si.tempCertDir)
-	require.NoError(t, err, "temporary certificate directory should exist")
-
-	// Start the server
-	err = sm.StartAll()
+	
+	// Verify certificates were created
+	_, err = os.Stat(certFile)
+	require.NoError(t, err, "certificate file should exist after first creation")
+	_, err = os.Stat(keyFile)
+	require.NoError(t, err, "key file should exist after first creation")
+	
+	// Get modification time of cert file
+	info1, err := os.Stat(certFile)
 	require.NoError(t, err)
-
+	modTime1 := info1.ModTime()
+	
+	// Wait a bit to ensure different modification times
 	time.Sleep(100 * time.Millisecond)
-
-	// Stop the server
-	err = sm.StopAll()
+	
+	// Second server creation - should reuse existing certificates
+	sm2 := NewManager()
+	testPort2 := getFreePort(t)
+	_, err = sm2.Add(Config{
+		Name:           "SSLTestServer2",
+		Host:           host,
+		Port:           testPort2,
+		Handler:        http.NewServeMux(),
+		SelfSignedSSL:  true,
+		ShutdownTimeout: 5 * time.Second,
+	})
 	require.NoError(t, err)
-
-	// Verify the temp directory has been cleaned up
-	_, err = os.Stat(si.tempCertDir)
-	assert.True(t, os.IsNotExist(err), "temporary certificate directory should be cleaned up after shutdown")
+	
+	// Get modification time of cert file after second creation
+	info2, err := os.Stat(certFile)
+	require.NoError(t, err)
+	modTime2 := info2.ModTime()
+	
+	// Verify the certificate was reused (same modification time)
+	assert.Equal(t, modTime1, modTime2, "certificate should be reused, not regenerated")
+	
+	// Clean up
+	sm1.StopAll()
+	sm2.StopAll()
 }
diff --git a/pkg/server/tls.go b/pkg/server/tls.go
index 30b35ae..fdadcc7 100644
--- a/pkg/server/tls.go
+++ b/pkg/server/tls.go
@@ -75,31 +75,85 @@ func generateSelfSignedCert(host string) (certPEM, keyPEM []byte, err error) {
 	return certPEM, keyPEM, nil
 }
 
-// saveCertToTempFiles saves certificate and key PEM data to temporary files.
-// Returns the file paths for the certificate and key, and the temporary directory path.
-func saveCertToTempFiles(certPEM, keyPEM []byte) (certFile, keyFile, tmpDir string, err error) {
-	// Create temporary directory
-	tmpDir, err = os.MkdirTemp("", "resolvespec-certs-*")
+// getCertDirectory returns the directory path for storing self-signed certificates.
+// Creates the directory if it doesn't exist.
+func getCertDirectory() (string, error) {
+	// Use a consistent directory in the user's cache directory
+	cacheDir, err := os.UserCacheDir()
 	if err != nil {
-		return "", "", "", fmt.Errorf("failed to create temp directory: %w", err)
+		// Fallback to current directory if cache dir is not available
+		cacheDir = "."
 	}
+	
+	certDir := filepath.Join(cacheDir, "resolvespec", "certs")
+	
+	// Create directory if it doesn't exist
+	if err := os.MkdirAll(certDir, 0700); err != nil {
+		return "", fmt.Errorf("failed to create certificate directory: %w", err)
+	}
+	
+	return certDir, nil
+}
 
-	certFile = filepath.Join(tmpDir, "cert.pem")
-	keyFile = filepath.Join(tmpDir, "key.pem")
+// isCertificateValid checks if a certificate file exists and is not expired.
+func isCertificateValid(certFile string) bool {
+	// Check if file exists
+	certData, err := os.ReadFile(certFile)
+	if err != nil {
+		return false
+	}
+	
+	// Parse certificate
+	block, _ := pem.Decode(certData)
+	if block == nil {
+		return false
+	}
+	
+	cert, err := x509.ParseCertificate(block.Bytes)
+	if err != nil {
+		return false
+	}
+	
+	// Check if certificate is expired or will expire in the next 30 days
+	now := time.Now()
+	expiryThreshold := now.Add(30 * 24 * time.Hour)
+	
+	if now.Before(cert.NotBefore) || now.After(cert.NotAfter) {
+		return false
+	}
+	
+	// Renew if expiring soon
+	if expiryThreshold.After(cert.NotAfter) {
+		return false
+	}
+	
+	return true
+}
 
+// saveCertToFiles saves certificate and key PEM data to persistent files.
+// Returns the file paths for the certificate and key.
+func saveCertToFiles(certPEM, keyPEM []byte, host string) (certFile, keyFile string, err error) {
+	// Get certificate directory
+	certDir, err := getCertDirectory()
+	if err != nil {
+		return "", "", err
+	}
+	
+	// Use consistent file names based on host
+	certFile = filepath.Join(certDir, fmt.Sprintf("%s-cert.pem", host))
+	keyFile = filepath.Join(certDir, fmt.Sprintf("%s-key.pem", host))
+	
 	// Write certificate
 	if err := os.WriteFile(certFile, certPEM, 0600); err != nil {
-		os.RemoveAll(tmpDir)
-		return "", "", "", fmt.Errorf("failed to write certificate: %w", err)
+		return "", "", fmt.Errorf("failed to write certificate: %w", err)
 	}
-
+	
 	// Write key
 	if err := os.WriteFile(keyFile, keyPEM, 0600); err != nil {
-		os.RemoveAll(tmpDir)
-		return "", "", "", fmt.Errorf("failed to write private key: %w", err)
+		return "", "", fmt.Errorf("failed to write private key: %w", err)
 	}
-
-	return certFile, keyFile, tmpDir, nil
+	
+	return certFile, keyFile, nil
 }
 
 // setupAutoTLS configures automatic TLS certificate management using Let's Encrypt.
@@ -135,32 +189,32 @@ func setupAutoTLS(domains []string, email, cacheDir string) (*tls.Config, error)
 }
 
 // configureTLS configures TLS for the server based on the provided configuration.
-// Returns the TLS config, certificate/key file paths (if applicable), and temp directory path (if applicable).
-func configureTLS(cfg Config) (*tls.Config, string, string, string, error) {
+// Returns the TLS config and certificate/key file paths (if applicable).
+func configureTLS(cfg Config) (*tls.Config, string, string, error) {
 	// Option 1: Certificate files provided
 	if cfg.SSLCert != "" && cfg.SSLKey != "" {
 		// Validate that files exist
 		if _, err := os.Stat(cfg.SSLCert); os.IsNotExist(err) {
-			return nil, "", "", "", fmt.Errorf("SSL certificate file not found: %s", cfg.SSLCert)
+			return nil, "", "", fmt.Errorf("SSL certificate file not found: %s", cfg.SSLCert)
 		}
 		if _, err := os.Stat(cfg.SSLKey); os.IsNotExist(err) {
-			return nil, "", "", "", fmt.Errorf("SSL key file not found: %s", cfg.SSLKey)
+			return nil, "", "", fmt.Errorf("SSL key file not found: %s", cfg.SSLKey)
 		}
 
 		// Return basic TLS config - cert/key will be loaded by ListenAndServeTLS
 		tlsConfig := &tls.Config{
 			MinVersion: tls.VersionTLS12,
 		}
-		return tlsConfig, cfg.SSLCert, cfg.SSLKey, "", nil
+		return tlsConfig, cfg.SSLCert, cfg.SSLKey, nil
 	}
 
 	// Option 2: Auto TLS (Let's Encrypt)
 	if cfg.AutoTLS {
 		tlsConfig, err := setupAutoTLS(cfg.AutoTLSDomains, cfg.AutoTLSEmail, cfg.AutoTLSCacheDir)
 		if err != nil {
-			return nil, "", "", "", fmt.Errorf("failed to setup AutoTLS: %w", err)
+			return nil, "", "", fmt.Errorf("failed to setup AutoTLS: %w", err)
 		}
-		return tlsConfig, "", "", "", nil
+		return tlsConfig, "", "", nil
 	}
 
 	// Option 3: Self-signed certificate
@@ -170,21 +224,43 @@ func configureTLS(cfg Config) (*tls.Config, string, string, string, error) {
 			host = "localhost"
 		}
 
-		certPEM, keyPEM, err := generateSelfSignedCert(host)
+		// Get certificate directory
+		certDir, err := getCertDirectory()
 		if err != nil {
-			return nil, "", "", "", fmt.Errorf("failed to generate self-signed certificate: %w", err)
+			return nil, "", "", fmt.Errorf("failed to get certificate directory: %w", err)
 		}
 
-		certFile, keyFile, tmpDir, err := saveCertToTempFiles(certPEM, keyPEM)
+		// Check for existing valid certificates
+		certFile := filepath.Join(certDir, fmt.Sprintf("%s-cert.pem", host))
+		keyFile := filepath.Join(certDir, fmt.Sprintf("%s-key.pem", host))
+
+		// If valid certificates exist, reuse them
+		if isCertificateValid(certFile) {
+			// Verify key file also exists
+			if _, err := os.Stat(keyFile); err == nil {
+				tlsConfig := &tls.Config{
+					MinVersion: tls.VersionTLS12,
+				}
+				return tlsConfig, certFile, keyFile, nil
+			}
+		}
+
+		// Generate new certificates
+		certPEM, keyPEM, err := generateSelfSignedCert(host)
 		if err != nil {
-			return nil, "", "", "", fmt.Errorf("failed to save self-signed certificate: %w", err)
+			return nil, "", "", fmt.Errorf("failed to generate self-signed certificate: %w", err)
+		}
+
+		certFile, keyFile, err = saveCertToFiles(certPEM, keyPEM, host)
+		if err != nil {
+			return nil, "", "", fmt.Errorf("failed to save self-signed certificate: %w", err)
 		}
 
 		tlsConfig := &tls.Config{
 			MinVersion: tls.VersionTLS12,
 		}
-		return tlsConfig, certFile, keyFile, tmpDir, nil
+		return tlsConfig, certFile, keyFile, nil
 	}
 
-	return nil, "", "", "", nil
+	return nil, "", "", nil
 }