The literature has recognised that implementing a safety management system is the most efficient way of allocating resources for safety, since it not only improves working conditions, but also positively influences employees' attitudes and behaviours with regards safety, consequently improving the safety climate. The safety climate and the safety management system are considered basic components of the firm's safety culture in various models. However, the literature has focused more on measuring the safety climate, while few studies have correctly tested the psychometric properties of the instruments used to measure how advanced the firm's safety management system is. This paper reviews the most important works on safety management, with the aim of developing a measurement scale operationalising the safety management system concept, and subsequently calculating its reliability and validity. For this purpose, exploratory factor analyses and confirmatory factor analyses are conducted, using structural equation models, on a sample of 455 Spanish companies. This scale provides organisations with a tool for evaluating their situation with regards safety management, as well as guidance about which areas they must improve if they wish to reduce occupational accidents. (C) 2006 Elsevier Ltd. All rights reserved.