ABSTRACT
BACKGROUND: Occupational Health and Safety Management Systems are becoming more widespread in organizations. Consequently, their effectiveness has become a core topic for researchers. This paper evaluates the performance of the Occupational Health and Safety Assessment Series 18001 specification in certified companies in Iran. METHODS: The evaluation is based on a comparison of specific criteria and indictors related to occupational health and safety management practices in three certified and three noncertified companies. RESULTS: Findings indicate that the performance of certified companies with respect to occupational health and safety management practices is significantly better than that of noncertified companies. CONCLUSION: Occupational Health and Safety Assessment Series 18001-certified companies have a better level of occupational health and safety; this supports the argument that Occupational Health and Safety Management Systems play an important strategic role in health and safety in the workplace.