A system and method for employing bytecode modification techniques for tracing services within an application server. Application servers, such as those based on the Java 2 Enterprise Edition (“J2EE”) standard, include a variety of different services. In one embodiment of the invention, a group of services executed on an application server are identified for tracing. For each service in the group, a group of entry and/or exit methods to be traced are identified. The group of entry/exit methods may represent entry and/or exit points to and from the service, respectively. Once the service's method are identified, the service's bytecode is modified based on the particular group of entry/exit methods specified. The service is then executed and method invocations of the bytecode modified entry/exit methods are registered.