Studies conducted to determine the efficacy of the ISM Code in the past include investigations of the trends of accident numbers and insurance claims and users’ perceptions. None of these, however, could produce a definitive conclusion. This is because both the use of safety outcome as well as the use of perception have inherent problems and are not reliable. This paper takes a different approach. It draws on wider research on management of workplace health and safety to ascertain whether or not employment and social conditions that support effective implementation of self-regulation are present in the maritime context. The findings reveal a considerable disparity between managers’ and seafarers’ understanding of the use of the Code resulting in a wide gap between its intended purpose and practice. The analysis shows that the critical factor is the lack of seafarers’ participation in management of workplace health and safety. The underlying causal factors for such lack of participation were located in seafarers’ poor employment condition and low-trust relationship with their managers.