Improvement of staffs’ productivity through job ethic promotion is the most important challenges in new millennium. Therefore, this research aimed to determine the relationship between job ethics and staffs’ productivity in Tehran University of Medical Sciences. This research was a descriptive-analytical cross-sectional study conducted in 2016-2017. The research population was all of the staff of Tehran University of Medical Sciences. The sample size calculated 375 by Cochran formula according to staff of the hospitals and university schools. The research tool was Cullen and Victor’s job ethnics and Hersey and Goldsmith’s staff productivity questionnaires. The data was analyzed by SPSS software version 22, and used average and standard deviation for descriptive results and parametric tests, for example Pearson and Multivariate Linear regression. There was significant correlation between staff’s productivity and their job ethics and its dimensions. Also, organizational justice had the more and righteousness had the less correlation with staff’s productivity. Moreover, the staff's gender had significant correlation with their productivity, but the age and educational degrees of the staff had negative significant correlation with their productivity. Ultimately, 86% of staff’s productivity variations were impressed by their job ethics and its dimensions. To increase productivity of staff, establishment of safe organizational climate, development of personal ethics, and consideration of ethical issues by managers and supervisors is suggested.