The assessment of undergraduate medical students in the clinical setting has become a key priority for medical educators. Facilitating the successful translation of undergraduate theoretical knowledge into safe and appropriate postgraduate clinical practice represents a challenge in medical education [1]. Poor clinical performance of newly qualified doctors has been highlighted as a major issue relating to patient safety [2]. Performance based assessment in the undergraduate setting may assist in addressing this issue by assessing ‘doing’ rather than ‘knowing’. The mini clinical evaluation exercise (Mini-CEX) is a formative assessment used to assess the performance of medical students in a clinical context. It incorporates assessment by, and feedback from, an assessor, based on the direct observation of a student–patient consultation [3]. Conducted in a series of stages, the Mini-CEX allows focused assessment of key competencies (see Box 1) [3].