The objective of this paper is to analyze the impact of the determinants of income smoothing in Tunis, which is to reduce the volatility of results. From a sample of 50 companies listed on the stock exchange of Tunis (Tunis Stock Exchange) during the period 2006-2010. We have developed an explanatory model of earnings management practices based on logistic regression. Our results show that the use of debt companies, calling the companies audited by a firm of "big six" provides a smoothing of results high. In the end, this original work of Tunisian data led to very carefully reinterpret the results of previous studies.