A method, system and program product for monitoring changes to a variable within a critical section of a threaded program. The method includes establishing, using a debugging tool, a watch for monitoring changes to a variable that occur outside of the critical section and executing a portion of the threaded program with a debugger. Further, the method includes determining, using the tool, whether or not a thread has executed a start breakpoint set for the critical section, if the thread has executed the start breakpoint set, determining whether or not the thread has executed an end breakpoint set for the critical section, and if the thread has not executed the end breakpoint set, displaying any watches triggered responsive to updates to the variable that occur outside of the critical section, such that, only updates to the variable that occur outside of the critical section will trigger the displaying.