The authors describe the Structured Clinical Interview for DSM-III-R Dissociative Disorders (SCID-D), which investigates five groups of dissociative symptoms (amnesia, depersonalization, derealization, identity confusion, and identity alteration) and systematically rates both the severity of individual symptoms and the evaluation of overall diagnosis of dissociative disorder. Preliminary findings from a study of 48 subjects with and without psychiatric diagnoses indicate good to excellent reliability and discriminant validity for the SCID-D as a diagnostic instrument for the five dissociative disorders and as a tool for the evaluation of dissociative symptoms encountered within nondissociative syndromes.