Core medical knowledge has been assessed for over fifty years and technical and communication skills for at least twenty. The assessment of professionalism however has failed to achieve recognition within this time frame. The interest in the assessment of professionalism and professional behaviour thus is a fairly recent development. This article will firstly clarify how professional behaviour assessment relates to other assessment methods using the framework proposed by Miller6. Thereafter a brief overview will be provided of the current "tool box" of methods available to assess professionalism. Data on the validity, reliability, feasibility, acceptability and educational utility of these "tools" as derived from published evidence will be reviewed. Subsequently a general overview of the way forward in the assessment of professionalism and professional behaviour will be given.