The purpose of the current study was to examine the validity and reliability of (Journal of Marital and Family Therapy 2003, 29, 209) Differentiation of Self Inventory‐Revised (DSI‐R; Skowron & Schmit, 2003) in Turkish adults. The DSI‐R was translated, independently back‐translated, and revised. Two independent samples of adults over the age of 25 were used. The original 46‐item DSI‐R was not supported by the data derived from Sample 1 (n = 221). However, a revised 20‐item, four‐factor model fit the data well. This 20‐item model was subsequently cross‐validated with a second sample of Turkish adults (n = 187). Scale scores showed adequate internal consistency, 5‐week test–retest reliability, and satisfactory convergent and criterion‐related validity. It was concluded that Turkish DSI‐R (DSI‐T) is a valid and reliable measure to assess an individual's differentiation level. In light of the findings, implications for the use of the DSI‐T and ideas for future research are discussed.