In Tanzania, poor enforcement of occupational health and safety (OHS) regulations has been associated with weak regulatory systems as well as lack of proper procedures on construction sites. However, the role of health and safety actors including organisational structures as enabling or disabling factors are under researched. This study employed qualitative research approach to discern the role of health and safety actors together with reasons for poor OHS enforcement on construction sites. Semi-structured interviews collected data from several health and safety actors within the sector. The salient findings from the study indicate that while legislation for enforcement of OHS exists, there is demonstrated lack of coordination including focus on formality, insufficient resources and overlapping roles regarding management of OHS. Power relations exercised by elected officials over regulators exacerbate these to influence public policy and purposeful violation of rules as a form of informal welfare policy for largely informal workers. This study recommends a need for promotion of safety leadership and behavioral change together with adequate supply of health and safety resources to the whole organisational system. Planning, tendering, designing and implementation stages of construction projects should embrace safety culture.