INTRODUCTION Increasing attention is being directed towards finding ways of assessing how well doctors perform in clinical practice. Current approaches rely on strategies directed at individuals only, but, in real life, doctors' work is characterised by multiple complex professional interactions. These interactions involve different kinds of teams and are embedded within the overall context and systems of care. In addition to individual factors, therefore, we propose that the performance of doctors in health care teams and systems will also impact on the overall quality of patient care. Assessing these dimensions, however, poses a number of challenges. STRATEGIES Taking a profile of a National Health Service, UK surgeon as an example, the team structures to which he or she may relate are illustrated. These include formal teams such as those found in the operating theatre, and those formed through various professional and collegial partnerships. The authors then propose a model for assessing doctors' performances in teams and systems, which incorporates the educational principles of continuous feedback to enhance future performance. DISCUSSION To implement the proposed model, a wide range of professional, educational and regulatory bodies must collaborate. This raises a number of important implications for the future roles and relationships of these bodies, which are discussed. A strong and constructive partnership will be essential if the full potential of a more inclusive and representative assessment approach is to be realised.