The purpose of this paper is: to assist professions to develop, in conjunction with National Office of Overseas Skills Recognition, the most suitable methods of assessing individuals against national competency standards; to provide advice on assessment methods likely to be practical and useful for the professions generally; and to provide advice on assessment methods consistent with the Commonwealth government's principles for the reform of the overseas skills recognition process. The authors consider alternative ways of conceptualising occupational competence and show how different conceptualisations can have very different implications for assessment. They briefly review the notion of competency based assessment. What are its distinguishing characteristics? How is it different from current practice? The review of previous attempts to implement competency based assessment reveals that these attempts have often been associated with detailed check lists of occupational skills. The purpose of assessment under this approach is to establish whether or not each listed skill has been mastered. It is concluded that a narrow, behaviouristic approach of this kind is unlikely to be appropriate for defining and assessing professional competence, and an approach to competency based assessment in the professions based on realistic, complex workplace problems as recommended instead.