Objectives: This paper aims at studying the infl uence of the organizational climate of a school on the occupational stress of the teachers. Material and Methods: The study population were all secondary schools teachers in Tehran in 2007. Using a multi-stage random sampling method, a sample volume of 220 people was determined using the Cochran formula. Two main instruments were used to measure the study variables: a 27-item questionnaire on organizational climate (four scales: open, engaged, disengaged and closed organizational climate, and a 53-item occupational stress questionnaire by Vingerhoets, employing 11 scales: Skill Discretion, Decision Authority, Task Control, Work and Time Pressure, Role Ambiguity, Physical Exertion, Hazardous Exposure, Job Insecurity, Lack of Meaningfulness, Social Support from Supervisor and Social Support from Coworkers. The frequency, percentage, and mean values were calculated and a stepwise regression analysis was performed to evaluate the statistical signifi cance of the fi ndings. Results and Conclusions: The study results revealed that: (a) 40.02% of secondary school teachers experience occupational stress at a moderate or higher level; (b) the rate of occupational stress among teachers can be predicted. using the scores on the school organizational climate; this predictability is highest for the open climate and gradually decreases through the engaged, and disengaged to the closed climate; (c) among the teachers working in the disengaged and closed climate, the rate of occupational stress signifi cantly exceeds that recorded among the teachers working in the open climate.