In this research, the authors test a model in which the regulatory focus of employees at work mediates the influence of leadership on employee behavior. In a nationally representative sample of 250 workers who responded over 2 time periods, prevention focus mediated the relationship of initiating structure to in-role performance and deviant behavior, whereas promotion focus mediated the relationship of servant leadership to helping and creative behavior. The results indicate that even though initiating structure and servant leadership share some variance in explaining other variables, each leadership style incrementally predicts disparate outcomes after controlling for the other style and dispositional tendencies. A new regulatory focus scale, the Work Regulatory Focus (WRF) Scale, also was developed and initially validated for this study. Implications for the results and the WRF Scale are discussed. (Contains 4 tables and 1 figure.)