Background: Job stress is one of the major threats of health and mental health in the workplace and is affected by intangible elements, such as social capital and organizational commitment in organizations. Objectives: The present study aimed at assessing job stress (JS) in staff of Kermanshah University of Medical Sciences, Iran, using organizational social capital (OSC) and organizational commitment (OC) questionnaires. Methods: This cross-sectional study was done in summer of 2014. From 311 distributed questionnaires, 302 persons who were selected by multi-stage stratified sampling, filled the questionnaires of Organizational Social Capital, Organizational Commitment and Job Stress (HSE). Data were analyzed using SPSS-18 (Pearson correlation and regression tests) and Amos18 (structural equation model (SEM)).