Objective: We aimed to determine Axis-I psychiatric disorders in patients with chronic pain (CP) and compare control subjects determined by a structured clinical interview. Another objective of the study was to examine whether there is an association between psychiatric disorders and quality of sleep, quality of life, and demographic and clinical characteristics in patients with CP. Design: The study sample was comprised of 108 patients with CP and 54 control subjects without pain. Psychiatric interviews were conducted with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV (SCID). Also used were the Hospital Anxiety and Depression Scale, Hamilton Depression Inventory, Short Form-36, and Pittsburgh Sleep Quality Index (PSQI). Results: The rate of any Axis-I psychiatric disorder stood at 66.7% (any mood disorder, 50%; any anxiety disorder, 33.3%; any somatoform disorder, 20.4%; any substance use disorder, 16.6%), significantly more common in the patients' group compared with the control group. The most common psychiatric disorder was major depression (49.1%) in subjects with CP. Female gender, numbers of localization, and neck and back localizations were significantly higher in the SCID (+) group than the SCID (-) group. A statistically significant difference was observed between the SCID (+) and SCID (-) groups regarding visual analogue scale, depression and anxiety scores, mental component summary score, and global PSQI scores. Conclusion: Results of this study suggest that psychiatric morbidity in patients with CP is frequently seen and may adversely affect quality of sleep and quality of life of the patients. Therefore, the patients with CP should be examined with respect to their mental status. © 2014 American Academy of Pain Medicine.