This paper analyses a number of relationships between virtual reality (VR) technology and ergonomics. The first part gives an overview of the field of virtual reality, identifies two main approaches (technology-driven vs. education) in current research, and discusses three important, although often ill-defined dimensions of current systems : presence, immersion and realism (or level of fidelity). Paper then sets out some of the main contributions made by ergonomics to VR and vice versa. First, three particular aspects of the contributions made by ergonomics by VR are discussed : detecting the users’ intention, analysing the operative representations, formalising the users’ models. Following this, the contributions made by VR to ergonomics are analysed on fow levels : assistance, training, work/task analysis, and the design of tools and workplaces. The paper concludes some implications for ergonomics in terms of practice and research : the development of more ecologically-oriented physical ergonomics, the integration of cognition, multi-modality and sensori-motor dimensions within a consistent framework for studying activities in VE, and the development of actual cooperation between users within VE.