This article describes the structure and rationale for an open-book approach in professional accountancy examinations. The concept of knowledge management and the recognition that some knowledge ought to be embedded in the minds of professional accountants while other knowledge ought to be readily accessible and capable of application forms the basis of this approach to open book assessment. The literature is examined and provides a context for the approach adopted. An initial analysis of an open-book examination provided a positive indication as to the feasibility of the proposals. Testing in a post-graduate accounting class was carried out with the results providing tentative support for this approach to open book assessment. (Contains 2 tables and 1 note.)