This paper explores the development and implementation of specific criteria to determine the level of clinical performance of postgraduate nursing students during the first year of a Master of Nursing course. The authors describe two commonly used clinical skill assessment tools and identify limitations of these tools for postgraduate nursing students. As a result of these limitations, Clinical Assessment Criteria (CAC) utilising the framework of Benner (1984) was developed. Inherent within the CAC is four levels of clinical nursing performance, which enable the nurse teacher and student to monitor the progression from novice to proficient levels of practice within a specialty area. Following a successful pilot study, the CAC was incorporated into clinical assessments in nine specialty postgraduate courses. Furthermore, the framework developed for the CAC can also be integrated into a variety of professional development domains.