Objective: The aim of this study is to demonstrate the validity and reliability of the Turkish Form of Muscle Dys-morphia Inventory (MDDI). Methods: This research was carried out with 196 professional male athletes which is 176 professional bodybuilder and 20 boxer in TRNC. Non-professional male athletes have not been taken into study. Beside MDDI, Body Cathexis Scale was used for concurrent validity. In reliability analysis internal consistency coefficients and item-total correlation analysis were calculated. In terms of examining the validity of the inventory, explanatory factor analysis, confirmatory factor analysis and correlation analysis with the Pearsons correlation analysis were performed. Results: The internal consistency of the MDDI was 0.81, item-total score correlation coefficients of the MDDI were between 0.36-0.58. In the explanatory factor analysis, for the sample adequacy Kaiser-Meier-Olkin coefficient was 0.789 and Bartlett coefficient was 938.85. Three-factor solution was obtained and the eigenvalue was 2.87, 2.64 and 2.31, explaining 60.18% of the total variance. Factor loadings of the items were between 0.56-0.88. Coefficient of Pearson correlation analysis was r=-0.52 Conclusion: Results demon-strated that the Turkish version of the MDDI was a valid and reliable. [Anadolu Psikiyatri Derg 2018; 19(0.200): 47-54]