The latest technological advancements in the domain of virtual reality (VR) have created new opportunities to use VR as a training platform for medical students and practitioners more broadly. Despite the growing interest in the use of VR as a training tool, a commonly identified gap in VR-training for medical education is the confidence in the long-term validity of the applications. A systematic literature review was undertaken to explore the extent of VR (in particular head-mounted displays) applications for medical training with an additional focus on validation measures. The papers included in this review discussed empirical case studies of specific applications; however, these were mostly concerned with human–computer interaction and were polarized between demonstrating that a conceptual technology solution was feasible for simulation or looked at specific areas of VR usability with little discussion on validation measures for long-term training effectiveness and outcomes. The review uncovered a wide range of ad hoc applications and studies in terms of technology vendors, environments, tasks, envisaged users and effectiveness of learning outcomes. This presents decision-making challenges for those seeking to adopt, implement and embed such systems in teaching practice. The authors of this paper then take a wider socio-technical systems perspective to understand how the holistic training system can be engineered and validated effectively as fit for purpose, through distillation of a generic set of requirements from the literature review to aid design specification and implementation, and to drive more informed and traceable validation of these types of systems. In this review, we have identified 92 requirement statements in 11 key areas against which a VR-HMD training system could be validated; these were grouped into design considerations, learning mechanisms and implementation considerations.