OBJECTIVE: The present study aimed to assess the validity and reliability of Geriatric Depression-15 Scale (GDS-15) in Turkish older adults and to compare the results with Diagnostic and Statistical Manual of Mental Disorders-fifth edition (DSM-5)depression criteria.METHODS: A total of 329 outpatients were enrolled. In the first step, the patients underwent the Mini-Mental State Examination. After assessing whether the patients meet the diagnosis of depression based on DSM-5 diagnostic criteria, anotherresearcher applied the long form of GDS. After sorting the items of short form out of the long form, two separate scores wereobtained. The scores of GDS-30 and GDS-15 scales were compared with the scores of DSM-5.RESULTS: The correlation of GDS-30 with GDS-15 was r=0.966 (p<0.001). The analysis performed considering DSM-5 criteria revealed that the sensitivity, specificity, positive predictive value, and negative predictive value of GDS-15 in determiningdepression were 92%, 91%, 76%, and 97%, respectively, when the cutoff value was taken as ≥5. The area under the receiver operating characteristics curve [95% confidence interval (CI)] was 0.97 (95% CI=0.947–0.996) for GDS-15 (p<0.001).The Cronbach alpha coefficient for the total scale was 0.920.CONCLUSION: GDS-15, just as GDS-30, is a beneficial scale in determining depression in older adults. This study providesan evidence for the validity and reliability of GDS-15 in Turkish elderly population and primary care centers.