This article (a) summarizes the literature concerning the dimensions of safety culture, (b) describes a method used to develop a questionnaire to identify the importance of these dimensions, and (c) includes a table of results that give the ranking of 18 safety culture dimensions. The results show that the most important dimensions include safety behaviour, awareness, contractor management, commitment, and training. A detailed analysis of the results show that the employees with the best culture recognize the importance of safety and safety regulations, they especially value life, and they consider safety as everyone's responsibility. (C) 2011 American Institute of Chemical Engineers Process Saf Prog, 2011