Organizational citizenship behaviors (OCB) are deemed indispensable due to their importance in promoting positive relationships among employees and involving employees in the organization's activities. OCB is believed to facilitate attainment of a hospital's goals and enhance a hospital's performance. The aim of this study is to extend the work of previous studies by providing an integrated model of OCB and demonstrate its applicability in a non-Western culture. Questionnaires were completed by 314 non-supervisory hospital nurses, each of whom was given a supervisor rating for their OCB. Exploratory factor analysis was used to assess the convergent and discriminant validity of the variables in the model. Multiple regression analysis was used because it provided estimates of net effects and explanatory power. The results showed that job satisfaction, supervisor support, job involvement, and procedural justices had significant effects on the nurses' citizenship behaviors. Since the study used a non-Western site in one of Taiwan's health care institutions, its overall findings should contribute to further understanding of the cross-cultural aspects of OCB.