diff --git a/.changeset/slow-terms-repeat.md b/.changeset/slow-terms-repeat.md
new file mode 100644
index 0000000000..808556f547
--- /dev/null
+++ b/.changeset/slow-terms-repeat.md
@@ -0,0 +1,6 @@
+---
+'astro': patch
+'@astrojs/node': patch
+---
+
+Handle binary data request bodies in the Node adapter
diff --git a/packages/astro/src/core/app/node.ts b/packages/astro/src/core/app/node.ts
index cb5356f630..c7e6f1ecad 100644
--- a/packages/astro/src/core/app/node.ts
+++ b/packages/astro/src/core/app/node.ts
@@ -7,7 +7,7 @@ import { App } from './index.js';
 
 const clientAddressSymbol = Symbol.for('astro.clientAddress');
 
-function createRequestFromNodeRequest(req: IncomingMessage, body?: string): Request {
+function createRequestFromNodeRequest(req: IncomingMessage, body?: Uint8Array): Request {
 	let url = `http://${req.headers.host}${req.url}`;
 	let rawHeaders = req.headers as Record<string, any>;
 	const entries = Object.entries(rawHeaders);
@@ -28,17 +28,10 @@ export class NodeApp extends App {
 	}
 	render(req: IncomingMessage | Request) {
 		if ('on' in req) {
-			let body: string | undefined = undefined;
+			let body = Buffer.from([]);
 			let reqBodyComplete = new Promise((resolve, reject) => {
 				req.on('data', (d) => {
-					if (body === undefined) {
-						body = '';
-					}
-					if (d instanceof Buffer) {
-						body += d.toString('utf-8');
-					} else if (typeof d === 'string') {
-						body += d;
-					}
+					body = Buffer.concat([body, d]);
 				});
 				req.on('end', () => {
 					resolve(body);
diff --git a/packages/integrations/node/test/api-route.test.js b/packages/integrations/node/test/api-route.test.js
index 034b53c07f..cd074ef273 100644
--- a/packages/integrations/node/test/api-route.test.js
+++ b/packages/integrations/node/test/api-route.test.js
@@ -31,4 +31,20 @@ describe('API routes', () => {
 		expect(json.length).to.equal(1);
 		expect(json[0].name).to.equal('Broccoli Soup');
 	});
+
+	it('Can get binary data', async () => {
+		const { handler } = await import('./fixtures/api-route/dist/server/entry.mjs');
+
+		let { req, res, done } = createRequestAndResponse({
+			method: 'POST',
+			url: '/binary',
+		});
+
+		handler(req, res);
+		req.send(Buffer.from(new Uint8Array([1, 2, 3, 4, 5])));
+
+		let [out] = await done;
+		let arr = Array.from(new Uint8Array(out.buffer));
+		expect(arr).to.deep.equal([5, 4, 3, 2, 1]);
+	});
 });
diff --git a/packages/integrations/node/test/fixtures/api-route/src/pages/binary.ts b/packages/integrations/node/test/fixtures/api-route/src/pages/binary.ts
new file mode 100644
index 0000000000..6b50bc341e
--- /dev/null
+++ b/packages/integrations/node/test/fixtures/api-route/src/pages/binary.ts
@@ -0,0 +1,11 @@
+
+export async function post({ request }: { request: Request }) {
+	let body = await request.arrayBuffer();
+	let data = new Uint8Array(body);
+	let r = data.reverse();
+	return new Response(r, {
+		headers: {
+			'Content-Type': 'application/octet-stream'
+		}
+	});
+}