diff --git a/client/src/pages/sites.tsx b/client/src/pages/sites.tsx
index f4e4178..1cd0fa2 100644
--- a/client/src/pages/sites.tsx
+++ b/client/src/pages/sites.tsx
@@ -1,6 +1,6 @@
 import { useState } from "react";
 import { useQuery, useMutation } from "@tanstack/react-query";
-import { Site, InsertSite } from "@shared/schema";
+import { Site, InsertSite, Customer } from "@shared/schema";
 import { Button } from "@/components/ui/button";
 import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card";
 import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle, DialogTrigger } from "@/components/ui/dialog";
@@ -40,6 +40,10 @@ export default function Sites() {
     queryKey: ["/api/sites"],
   });
 
+  const { data: customers } = useQuery<Customer[]>({
+    queryKey: ["/api/customers"],
+  });
+
   const form = useForm<InsertSite>({
     resolver: zodResolver(insertSiteSchema),
     defaultValues: {
@@ -228,6 +232,32 @@ export default function Sites() {
                   )}
                 />
 
+                <FormField
+                  control={form.control}
+                  name="customerId"
+                  render={({ field }) => (
+                    <FormItem>
+                      <FormLabel>Cliente</FormLabel>
+                      <Select onValueChange={field.onChange} value={field.value || undefined}>
+                        <FormControl>
+                          <SelectTrigger data-testid="select-customer">
+                            <SelectValue placeholder="Seleziona cliente (opzionale)" />
+                          </SelectTrigger>
+                        </FormControl>
+                        <SelectContent>
+                          <SelectItem value="">Nessun cliente</SelectItem>
+                          {customers?.map((customer) => (
+                            <SelectItem key={customer.id} value={customer.id}>
+                              {customer.name}
+                            </SelectItem>
+                          ))}
+                        </SelectContent>
+                      </Select>
+                      <FormMessage />
+                    </FormItem>
+                  )}
+                />
+
                 <FormField
                   control={form.control}
                   name="location"
@@ -489,6 +519,32 @@ export default function Sites() {
                 )}
               />
 
+              <FormField
+                control={editForm.control}
+                name="customerId"
+                render={({ field }) => (
+                  <FormItem>
+                    <FormLabel>Cliente</FormLabel>
+                    <Select onValueChange={field.onChange} value={field.value || undefined}>
+                      <FormControl>
+                        <SelectTrigger data-testid="select-edit-customer">
+                          <SelectValue placeholder="Seleziona cliente (opzionale)" />
+                        </SelectTrigger>
+                      </FormControl>
+                      <SelectContent>
+                        <SelectItem value="">Nessun cliente</SelectItem>
+                        {customers?.map((customer) => (
+                          <SelectItem key={customer.id} value={customer.id}>
+                            {customer.name}
+                          </SelectItem>
+                        ))}
+                      </SelectContent>
+                    </Select>
+                    <FormMessage />
+                  </FormItem>
+                )}
+              />
+
               <FormField
                 control={editForm.control}
                 name="location"