diff --git a/lib/appenders/categoryFilter.js b/lib/appenders/categoryFilter.js
new file mode 100644
index 0000000..7a35624
--- /dev/null
+++ b/lib/appenders/categoryFilter.js
@@ -0,0 +1,24 @@
+var levels = require('../levels');
+var log4js = require('../log4js');
+
+function contains(list, value) {
+    return list.indexOf(value) !== -1;
+}
+
+function categoryFilter (excludes, appender) {
+    if (typeof(excludes) === 'string') excludes = [excludes];
+    return function(logEvent) {
+        if (excludes.indexOf(logEvent.categoryName) === -1) {
+            appender(logEvent);
+        }
+    }
+}
+
+function configure(config) {
+    log4js.loadAppender(config.appender.type);
+    var appender = log4js.appenderMakers[config.appender.type](config.appender);
+    return categoryFilter(config.exclude, appender);
+}
+
+exports.appender = categoryFilter;
+exports.configure = configure;
diff --git a/test/categoryFilter-test.js b/test/categoryFilter-test.js
new file mode 100644
index 0000000..30dd42d
--- /dev/null
+++ b/test/categoryFilter-test.js
@@ -0,0 +1,79 @@
+'use strict';
+
+var vows = require('vows')
+, fs = require('fs')
+, assert = require('assert');
+
+function remove(filename) {
+    try {
+        fs.unlinkSync(filename);
+    } catch (e) {
+        //doesn't really matter if it failed
+    }
+}
+
+vows.describe('log4js categoryFilter').addBatch({
+    'appender': {
+        topic: function() {
+
+            var log4js = require('../lib/log4js'), logEvents = [], webLogger, appLogger;
+            log4js.clearAppenders();
+            var appender = require('../lib/appenders/categoryFilter').appender(['app'], function(evt) { logEvents.push(evt); });
+            log4js.addAppender(appender, ["app","web"]);
+
+            webLogger = log4js.getLogger("web");
+            appLogger = log4js.getLogger("app");
+
+            webLogger.debug('This should get logged');
+            appLogger.debug('This should not');
+            webLogger.debug('Hello again');
+            log4js.getLogger('db').debug('This shouldn\'t be included by the appender anyway');
+
+            return logEvents;
+        },
+        'should only pass matching category' : function(logEvents) {
+            assert.equal(logEvents.length, 2);
+            assert.equal(logEvents[0].data[0], 'This should get logged');
+            assert.equal(logEvents[1].data[0], 'Hello again');
+        }
+    },
+
+    'configure': {
+        topic: function() {
+            var log4js = require('../lib/log4js')
+          , logger, weblogger;
+
+            remove(__dirname + '/categoryFilter-web.log');
+            remove(__dirname + '/categoryFilter-noweb.log');
+
+            log4js.configure('test/with-categoryFilter.json');
+            logger = log4js.getLogger("app");
+            weblogger = log4js.getLogger("web");
+
+            logger.info('Loading app');
+            logger.debug('Initialising indexes');
+            weblogger.info('00:00:00 GET / 200');
+            weblogger.warn('00:00:00 GET / 500');
+            //wait for the file system to catch up
+            setTimeout(this.callback, 100);
+        },
+        'tmp-tests.log': {
+            topic: function() {
+                fs.readFile(__dirname + '/categoryFilter-noweb.log', 'utf8', this.callback);
+            },
+            'should contain all log messages': function(contents) {
+                var messages = contents.trim().split('\n');
+                assert.deepEqual(messages, ['Loading app','Initialising indexes']);
+            }
+        },
+        'tmp-tests-web.log': {
+            topic: function() {
+                fs.readFile(__dirname + '/categoryFilter-web.log','utf8',this.callback);
+            },
+            'should contain only error and warning log messages': function(contents) {
+                var messages = contents.trim().split('\n');
+                assert.deepEqual(messages, ['00:00:00 GET / 200','00:00:00 GET / 500']);
+            }
+        }
+    }
+}).export(module);
diff --git a/test/with-categoryFilter.json b/test/with-categoryFilter.json
new file mode 100644
index 0000000..7998cc8
--- /dev/null
+++ b/test/with-categoryFilter.json
@@ -0,0 +1,23 @@
+{
+  "appenders": [
+    { 
+      "type": "categoryFilter",
+      "exclude": "web",
+      "appender": {
+        "type": "file",
+        "filename": "test/categoryFilter-noweb.log", 
+        "layout": { 
+          "type": "messagePassThrough" 
+        } 
+      }
+    },
+    { 
+      "category": "web", 
+      "type": "file",
+      "filename": "test/categoryFilter-web.log", 
+      "layout": { 
+        "type": "messagePassThrough" 
+      } 
+    }
+  ]
+}