diff --git a/cli.js b/cli.js
index c776bb699..2189b23af 100755
--- a/cli.js
+++ b/cli.js
@@ -24,6 +24,7 @@ var meow = require('meow');
 var Promise = require('bluebird');
 var pkgConf = require('pkg-conf');
 var isCi = require('is-ci');
+var chokidar = require('chokidar');
 var colors = require('./lib/colors');
 var verboseReporter = require('./lib/reporters/verbose');
 var miniReporter = require('./lib/reporters/mini');
@@ -48,6 +49,7 @@ var cli = meow([
 	'  --tap, -t        Generate TAP output',
 	'  --verbose, -v    Enable verbose output',
 	'  --no-cache       Disable the transpiler cache',
+	'  --watch, -w      Run tests when files change',
 	'',
 	'Examples',
 	'  ava',
@@ -68,14 +70,16 @@ var cli = meow([
 		'fail-fast',
 		'verbose',
 		'serial',
-		'tap'
+		'tap',
+		'watch'
 	],
 	default: conf,
 	alias: {
 		t: 'tap',
 		v: 'verbose',
 		r: 'require',
-		s: 'serial'
+		s: 'serial',
+		w: 'watch'
 	}
 });
 
@@ -95,6 +99,7 @@ var api = new Api(cli.input.length ? cli.input : arrify(conf.files), {
 
 var logger = new Logger();
 logger.api = api;
+logger.watch = cli.flags.watch;
 
 if (cli.flags.tap) {
 	logger.use(tapReporter());
@@ -112,17 +117,32 @@ api.on('error', logger.unhandledError);
 api.on('stdout', logger.stdout);
 api.on('stderr', logger.stderr);
 
-api.run()
-	.then(function () {
-		logger.finish();
-		logger.exit(api.failCount > 0 || api.rejectionCount > 0 || api.exceptionCount > 0 ? 1 : 0);
-	})
-	.catch(function (err) {
-		if (err.name === 'AvaError') {
-			console.log('  ' + colors.error(figures.cross) + ' ' + err.message);
-		} else {
-			console.error(colors.stack(err.stack));
-		}
-
-		logger.exit(1);
+function run() {
+	api.run()
+		.then(function () {
+			logger.finish();
+			logger.exit(api.failCount > 0 || api.rejectionCount > 0 || api.exceptionCount > 0 ? 1 : 0);
+		})
+		.catch(function (err) {
+			if (err.name === 'AvaError') {
+				console.log('  ' + colors.error(figures.cross) + ' ' + err.message);
+			} else {
+				console.error(colors.stack(err.stack));
+			}
+
+			logger.exit(1);
 	});
+}
+
+run();
+
+var cwd = process.cwd();
+var watcher = chokidar.watch(cwd, {
+	persistent: cli.flags.watch,
+	ignored: [cwd + '/node_modules', cwd + '/.git'],
+	followSymlinks: false
+});
+
+watcher.on('change', function (filepath) {
+	run();
+});
diff --git a/lib/logger.js b/lib/logger.js
index 930c95d0a..b98d7af96 100644
--- a/lib/logger.js
+++ b/lib/logger.js
@@ -75,6 +75,10 @@ Logger.prototype.exit = function (code) {
 	process.stdout.write('');
 	process.stderr.write('');
 
+	if (this.watch) {
+		return;
+	}
+
 	// timeout required to correctly flush IO on Node.js 0.10 on Windows
 	setTimeout(function () {
 		process.exit(code);
diff --git a/package.json b/package.json
index 17d3a87f0..a567b8601 100644
--- a/package.json
+++ b/package.json
@@ -88,6 +88,7 @@
     "bluebird": "^3.0.0",
     "caching-transform": "^1.0.0",
     "chalk": "^1.0.0",
+    "chokidar": "^1.4.2",
     "cli-cursor": "^1.0.2",
     "co-with-promise": "^4.6.0",
     "commondir": "^1.0.1",