The quality of service rendered by audit firms is an essential element in improving the efficiency and effectiveness (performance) of audit firms. In addition, this quality of audit apprehended by the quality of the auditor (competence and independence) depends on the contextual context, the environment in which it is exercised and the behavior of the actors put in place. Based on research perceived by audit firms, the present de study aims to identify the link between contingency factors and performance. Based on the Churchill paradigm (1979), our research data are articulated around a qualitative phase (10 semi-directive interviews) and quantitative (52 audit firms) collected in the cities of Douala and Yaoundé. Econometric analyzes using the multiple linear regression technique show that factors related to auditor competence (generic factors) and independence (specific factors) determines the quality of the performance of firms.