A dynamic instrumentation method and apparatus which may trace, debug, and profile the execution of a running program without affecting the operation of the program, are provided. According to the method, a break instruction is inserted and executed at start of execution of a first instruction and immediately after execution of the last instruction of a function constituting the program. Environment values of the function before and after execution may be identified. The program may be dynamically instrumented without being affected by any tracing or debugging operations.