The onset of injury and disability can have a significant negative effect on individuals' social, interpersonal and vocational participation. This in turn impacts on individuals' current and future earning capacity. An objective assessment of post-injury work capacity is often sought through legal processes to determine the extent of this loss. Onset of disability does not necessarily mean lack of ability to work. Changes in employment potential are, however, commonplace post-injury. This paper canvasses a range of issues confronting professionals who assess employment potential following injury, especially in medico-legal settings. What needs to be assessed, what assumptions need to be avoided and what practices undermine reliable and valid vocational assessment are discussed. Recommendations and suggestions about how to perform employability assessment to meet the standards required by the court system of expert witnesses are also outlined.