A method and system monitor and diagnose the performance of remote method invocations using bytecode instrumentation in distributed multi-tier applications. The method and system use automated instrumentation of client application bytecode and server application bytecode with sensors to measure performance of remote method invocations and operations performed during remote method invocations. Performance information is captured for each remote method invocation separately, allowing performance diagnosis of multithreaded execution of remote method invocations, so that throughput and response time information are accurate even when other threads perform remote method invocations concurrently. The captured performance metrics include throughput and response time of remote method invocation, object serialization, and transport. The performance metrics are captured per remote method invocation. Performance metrics may be sent to a processing unit for storage, analysis, and correlation.