diff --git a/cmd/renew.go b/cmd/renew.go
index 5f1c1bb7..e7bf6625 100644
--- a/cmd/renew.go
+++ b/cmd/renew.go
@@ -1,27 +1,110 @@
 package cmd
 
 import (
-	"fmt"
+	"encoding/json"
+	"io/ioutil"
+	"path"
+	"time"
 
+	"github.com/gianluca311/lego/cmd/utils"
 	"github.com/spf13/cobra"
+	"github.com/xenolf/lego/acme"
 )
 
+func renewHandler(cmd *cobra.Command, args []string) {
+	conf, _, client := utils.Setup(RootCmd)
+
+    domains, err := RootCmd.PersistentFlags().GetStringSlice("domains")
+    if err != nil {
+        logger().Fatalln(err.Error())
+    }
+    
+	if len(domains) <= 0 {
+		logger().Fatal("Please specify at least one domain.")
+	}
+
+	domain := domains[0]
+
+	// load the cert resource from files.
+	// We store the certificate, private key and metadata in different files
+	// as web servers would not be able to work with a combined file.
+	certPath := path.Join(conf.CertPath(), domain+".crt")
+	privPath := path.Join(conf.CertPath(), domain+".key")
+	metaPath := path.Join(conf.CertPath(), domain+".json")
+
+	certBytes, err := ioutil.ReadFile(certPath)
+	if err != nil {
+		logger().Fatalf("Error while loading the certificate for domain %s\n\t%s", domain, err.Error())
+	}
+    
+    days, err := cmd.PersistentFlags().GetInt("days")
+    if err != nil {
+        logger().Fatalln(err.Error())
+    }
+    
+	if days > 0 {
+		expTime, err := acme.GetPEMCertExpiration(certBytes)
+		if err != nil {
+			logger().Printf("Could not get Certification expiration for domain %s", domain)
+		}
+
+		if int(expTime.Sub(time.Now()).Hours()/24.0) > days {
+			return
+		}
+	}
+
+	metaBytes, err := ioutil.ReadFile(metaPath)
+	if err != nil {
+		logger().Fatalf("Error while loading the meta data for domain %s\n\t%s", domain, err.Error())
+	}
+
+	var certRes acme.CertificateResource
+	err = json.Unmarshal(metaBytes, &certRes)
+	if err != nil {
+		logger().Fatalf("Error while marshalling the meta data for domain %s\n\t%s", domain, err.Error())
+	}
+
+    reusekey, err := cmd.PersistentFlags().GetBool("reuse-key")
+    if err != nil {
+        logger().Fatalln(err.Error())
+    }
+    
+	if reusekey {
+		keyBytes, err := ioutil.ReadFile(privPath)
+		if err != nil {
+			logger().Fatalf("Error while loading the private key for domain %s\n\t%s", domain, err.Error())
+		}
+		certRes.PrivateKey = keyBytes
+	}
+
+	certRes.Certificate = certBytes
+
+    nobundle, err := cmd.PersistentFlags().GetBool("no-bundle")
+    if err != nil {
+        logger().Fatalln(err.Error())
+    }
+    
+	newCert, err := client.RenewCertificate(certRes, !nobundle)
+	if err != nil {
+		logger().Fatalf("%s", err.Error())
+	}
+
+	utils.SaveCertRes(newCert, conf)
+}
+
 // renewCmd represents the renew command
 var renewCmd = &cobra.Command{
 	Use:   "renew",
 	Short: "Renew a certificate",
-	Long: ``,
-	Run: func(cmd *cobra.Command, args []string) {
-		// TODO: Work your own magic here
-		fmt.Println("renew called")
-	},
+	Long:  ``,
+	Run:   renewHandler,
 }
 
 func init() {
 	RootCmd.AddCommand(renewCmd)
 
 	renewCmd.PersistentFlags().Int("days", 0, "The number of days left on a certificate to renew it.")
-    renewCmd.PersistentFlags().Bool("resuse-key", false, "Used to indicate you want to reuse your current private key for the new certificate.")
-    renewCmd.PersistentFlags().Bool("no-bundle", false, "Do not create a certificate bundle by adding the issuers certificate to the new certificate.")
+	renewCmd.PersistentFlags().Bool("resuse-key", false, "Used to indicate you want to reuse your current private key for the new certificate.")
+	renewCmd.PersistentFlags().Bool("no-bundle", false, "Do not create a certificate bundle by adding the issuers certificate to the new certificate.")
 
 }