The authors of this study sought to quantify the beneficial effect of goal setting on work performance, and to characterize the persistence or deterioration of goal-directed behavior over time. Twenty-six participants completed a computer-based data entry task. Performance was measured during an initial baseline, a goal setting intervention that consisted of either a high, unattainable goal (high goal condition) or a low, attainable goal (low goal condition), followed by a return to baseline, and a second goal setting intervention (the alternate goal to the first goal). In the fifth condition, each participant was given the choice to work in either the high or low goal condition. Greater performance increases were reliably observed during the high goal condition than during the low goal condition, but patterns of persistence or deterioration varied across participants. The implications of the findings for the development and understanding of goal setting interventions in the workplace are explored.