Purpose : The purposes of this study is twofold: (a) to investigate the effect of job stress and organizational climate on the organizational effectiveness of hospital nurses, and (2) to examine the moderating effect of organizational climate on job stress. Method : Three organizational effectiveness variables(e .g., job satisfaction, organizational committment and group productivity) as outcomes variables were examined. The sample consisted of 602 nurses from 5 general hospitals affiliated university. Data were collected with self-administrated questionnaires and analyzed using hierarchical regression. Results : It was found that: (a) seven job stress variables(e. g., workload, role conflict, schedule, lack of knowledge, conflict with superior, conflict with other personnel and conflict with patients) have negative effect on job satisfaction and organizational committment; (b) organizational climate have positive main effects on job satisfaction and organizational committment; (c) the negative effects of job stress variables on job satisfaction and organizational committment are not moderated by organizational climate. Conclusion : Organizational climate mediates the effects of job stress on group productivity, but the size of the mediating effects was small. Various outcome variables need to be discussed further research.