Previous research has shown the important role that employees play in improving the organisation's safety outcomes. This work analyses the effect of safety leadership and working conditions on employees' safety behaviours. For this purpose, the authors develop and test a structural equation model on a sample of 103 process industry organisations located in Spain. The results show that safety compliance is conditioned by work pressure, environmental conditions and occupational hazards, and co-worker support, while safety participation is conditioned by environmental conditions and occupational hazards, safety incentives, and co-worker support. The results also show that safety leadership has a negative effect on work pressure, and a positive effect on environmental conditions and occupational hazards and on safety incentives. This work offers guidelines to leaders in process industries about the behaviours and policies that they should adopt if they wish to improve their safety outcomes.