This article considers how professional knowledge should be assessed. It is maintained that the assessment of professional know-how raises distinctive issues from the assessment of know-how more generally. Intellectualist arguments which suggest that someone's giving an account of how to F should suffice for attributing to them knowledge of how to F are set out. The arguments fail to show that there is no necessary distinction between two kinds of know-how, namely the ability to F and knowing that w is (...) a way to F, such that the latter is more fundamental. The consequences of this failure for our understanding of professional assessment are then considered. The issue of the assessment of tacit knowledge is then addressed. It is concluded that there is no context-dependent codifiable or articulable propositional knowledge of how to F which could be substituted for being able to F and that therefore tacit knowledge can only be assessed in performance. The parallel with Gettier cases is reviewed and it is concluded that the provenance of accounts of and justifications for the attribution of know-how are not matters of indifference to its assessment. Finally, the question of evaluability or what Ryle would have called the applicability of intelligence epithets is discussed in relation to its relevance to our procedures for assessing practical knowledge. Once again, it is concluded that excellent performance is necessary to attribute excellence in know-how. However, the ability to give an account of how and why an agent would do something in hypothetical circumstances is also very important for the assessment of professional knowledge. (shrink)