This study examines the technical, allocative, and cost efficiency of conventional and participation banks in Turkey with data envelopment analysis (DEA) method. In the wake of finding technical, allocative, and cost efficiency results by DEA intermediation approach, Tobit regression analysis is used to determine the factors influencing the efficiency. The main purpose of this paper is analyzing efficiency of the banking system in Turkey and compare the efficiency of participation banks and conventional banks. The results of DEA indicate that average participation bank efficiency is higher than the average conventional bank efficiency each year. Regarding Tobit regression analysis, while expenses and loan quality have a significantly negative relationship with efficiency of conventional banks, they have a significantly positive relationship with the efficiency of participation banks. While the total loans have a significantly positive relationship, external variables have a significantly negative relationship with efficiency of both types of the banks. Copyright (C) 2017, Borsa Istanbul Anonim Sirketi. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.