Knowledge Management (KM) capabilities are critical for Small and Medium Enterprises (SMEs). It allows them to be more competitive, and to leverage one of their key resources: Knowledge. However, the body of knowledge on KM in SMEs is very scarce, and most of the attempts to implement KM in SMEs fail, because of the inadequate models provided. In order to achieve successful km implementation, SMEs specificities must be studied. The purpose of this paper is to introduce a tool allowing us to describe precisely SMEs, in regard of KM. It is based on an extensive literature review on knowledge management in SMEs, knowledge management and SMEs characteristics, and critical success factors. We identified 96 elements that can be used to provide data on the way to achieve an efficient knowledge management implementation and use it in a SME. By answering a set of questions on these elements, the user is guided in the construction of a knowledge management system fitting the needs and the specificities of the enterprise while using as little resources as possible. By providing an accurate description of a SME, as well as a tailor-made knowledge management system, our tool increases the probability of a successful knowledge management implementation.