The aim of the research is to propose a Data Envelopment Analysis (DEA) methodology for the performance evaluation of 76 dealers of Hyundai in Turkey in terms of after sales services such as repair and maintenance. Through this work, appropriate inputs and outputs are determined and the DEA methodology is applied for 76 dealers. DEA is a multi-criteria decision making model that can be used to determine rank orders of units when there are given inputs and outputs. Three inputs and four outputs are determined by the authors and expert opinion. After data collection and DEA analysis, we reported the ranks of 76 dealers after sales services and classify the ranks by regions in order to spotlight certain regional considerations (such as popular touristic destinations) in terms of after sales performance. Research is limited to a specific brand and can be extended to include other brands in the future. Also, other after sales services such as appliance repair can be included. After sales service personnel can easily use the method by Excel and can see their performance with respect to other dealers. As dealers can see performance based incentives becoming a major part of their total profits being able to see the relative positions among the many dealers would have practical implications.