Safety training of migrant workers in construction has focused on technical skills with limited attention to non-technical skills, which support safety training transfer to the worksite, both immediately after training and in the long term. Using realist evaluation as our theoretical framework, this study explores the transfer of two key non-technical skills to construction sites: communication and decision-making. Trained workers completed questionnaires post-training and after six months. A moderated mediation model found an indirect link through training transfer between communication and decision-making skills immediately post-training and six months later. The results also revealed that high levels of safety self-efficacy moderated the relationship between communication, but not decision-making, safety skills post-training and the extent to which trained workers reported transferring these skills. The study has important practical implications, showing the significance of training transfer of non-technical skills, such as communication and decision-making, to the worksite.