PURPOSE: This study was done to examine the effects of nurses' perception of servant leadership on leader effectiveness, satisfaction and promoting additional effort. The focus was the mediating effects of leader trust and value congruence. METHODS: Data were collected from 361 RN-BSN students and nurses participating in nationally attended in-service training programs. Data were analyzed using descriptive statistics and structural analysis with SPSS 17.0 windows program and Amos 7.0. RESULTS: Direct effects of nurses' perception of servant leadership were negative, but mediating effects of trust and value congruency were positively correlated with leader effectiveness, satisfaction and additional effort, that is servant leadership should be effective through mediating factors. CONCLUSION: The study results indicate that if the middle managers of nurses can build leader trust and value congruency between nurses through servant leadership, leader effectiveness, satisfaction and additional effort on the part of the nurses could result in a positive change in the long term.