The contribution of this paper is twofold; it aims to : propose a description of accounting data systems (ADS) in SMEs, identify contingency factors which influence them. The quantitative study, carried out by face-to-face directive interviews with 71 managers of Tunisian industrial SMEs, highlights that : the accounting data management is a mandatory anchor for all managers, including those of smaller companies, but the Accounting Data Systems (ADS) in SMEs are rarely complex and are, thereby, specific, if the context in which the organization functions is a source of constraint, the leader maintains a dominant role.