Method, system and article of manufacture for monitoring variables. In one embodiment, information generated by a compiler is used to determine which variables need to be updated when performing a step, a “run to cursor” operation, and when a breakpoint is hit. This may be accomplished by providing as debugger data which variables may be affected at each statement of a program and a control flow graph for the program or procedure. The information about which variables may be affected can be stored as individual variables or sets of variables. When execution of the program being debugged is halted, only those variables whose values may have changed are refreshed in a variables window of a user interface.