diff --git a/packages/start/src/config/fs-routes/fs-watcher.ts b/packages/start/src/config/fs-routes/fs-watcher.ts
new file mode 100644
index 000000000..1965e9c65
--- /dev/null
+++ b/packages/start/src/config/fs-routes/fs-watcher.ts
@@ -0,0 +1,79 @@
+import type {
+  EnvironmentModuleNode,
+  FSWatcher,
+  ModuleGraph,
+  ModuleNode,
+  PluginOption,
+  ViteDevServer
+} from "vite";
+import { moduleId, RouterBuilder } from "./index.js";
+
+interface CompiledRouter {
+  removeRoute(path: string): void;
+  addRoute(path: string): void;
+  updateRoute(path: string): void;
+  addEventListener(event: "reload", handler: () => void): void;
+  removeEventListener(event: "reload", handler: () => void): void;
+}
+
+function setupWatcher(watcher: FSWatcher, routes: CompiledRouter): void {
+  watcher.on("unlink", path => routes.removeRoute(path));
+  watcher.on("add", path => routes.addRoute(path));
+  watcher.on("change", path => routes.updateRoute(path));
+}
+
+function createRoutesReloader(
+  server: ViteDevServer,
+  routes: CompiledRouter,
+  environment: "client" | "server"
+): () => void {
+  routes.addEventListener("reload", handleRoutesReload);
+  return () => routes.removeEventListener("reload", handleRoutesReload);
+
+  function handleRoutesReload(): void {
+    if (environment === "server") {
+      // Handle server environment HMR reload
+      const serverEnv = server.environments.server;
+      if (serverEnv && serverEnv.moduleGraph) {
+        const mod: EnvironmentModuleNode | undefined =
+          serverEnv.moduleGraph.getModuleById(moduleId);
+        if (mod) {
+          const seen = new Set<EnvironmentModuleNode>();
+          serverEnv.moduleGraph.invalidateModule(mod, seen);
+        }
+      }
+    } else {
+      // Handle client environment HMR reload
+      const { moduleGraph }: { moduleGraph: ModuleGraph } = server;
+      const mod: ModuleNode | undefined = moduleGraph.getModuleById(moduleId);
+      if (mod) {
+        const seen = new Set<ModuleNode>();
+        moduleGraph.invalidateModule(mod, seen);
+        server.reloadModule(mod);
+      }
+    }
+
+    if (!server.config.server.hmr) {
+      server.ws.send({ type: "full-reload" });
+    }
+  }
+}
+
+export const fileSystemWatcher = (
+  routers: Record<"client" | "server", RouterBuilder>
+): PluginOption => {
+  const plugin: PluginOption = {
+    name: "fs-watcher",
+    apply: "serve",
+    async configureServer(server: ViteDevServer) {
+      Object.keys(routers).forEach(environment => {
+        const router = routers[environment as keyof typeof routers](server.config);
+        (globalThis as any).ROUTERS[environment] = router;
+
+        setupWatcher(server.watcher, router);
+        createRoutesReloader(server, router, environment as keyof typeof routers);
+      });
+    }
+  };
+  return plugin;
+};
diff --git a/packages/start/src/config/fs-routes/index.ts b/packages/start/src/config/fs-routes/index.ts
index 9f721a99e..20ff16b46 100644
--- a/packages/start/src/config/fs-routes/index.ts
+++ b/packages/start/src/config/fs-routes/index.ts
@@ -1,5 +1,7 @@
 import { relative } from "node:path";
 import type { PluginOption, ResolvedConfig } from "vite";
+
+import { fileSystemWatcher } from "./fs-watcher.js";
 import type { BaseFileSystemRouter } from "./router.js";
 import { treeShake } from "./tree-shake.js";
 
@@ -14,11 +16,8 @@ export interface FsRoutesArgs {
   handlers: Record<"client" | "server", string>;
 }
 
-export function fsRoutes({
-  routers,
-  handlers
-}: FsRoutesArgs): Array<PluginOption> {
-  (globalThis as any).ROUTERS = {};
+export function fsRoutes({ routers, handlers }: FsRoutesArgs): Array<PluginOption> {
+  (globalThis as any).ROUTERS = routers;
 
   return [
     {
@@ -34,11 +33,7 @@ export function fsRoutes({
         if (id !== moduleId) return;
         const js = jsCode();
 
-        const router = routers[this.environment.name as keyof typeof routers](
-          this.environment.config
-        );
-
-        (globalThis as any).ROUTERS[this.environment.name] = router;
+        const router = (globalThis as any).ROUTERS[this.environment.name];
 
         const routes = await router.getRoutes();
 
@@ -91,7 +86,8 @@ export default ${routesCode}`;
         return code;
       }
     },
-    treeShake()
+    treeShake(),
+    fileSystemWatcher(routers)
   ];
 }