Assessment of medical technologies is a multidisciplinary activity requiring the participation of engineers, clinicians and social scientists. The contribution of engineers has often been confined to the early stages of technical assessment. However, engineers have important inputs to make throughout the assessment process in their roles of developers, users and managers of technology. Engineers have found collaboration with clinical researchers possible through hospital-based work, but must also develop links with economists and other social scientists if they are to make a full contribution to comprehensive technology assessment.