Objective: This study presents the current prevalence of Axis I and Axis II psychiatric diagnoses and factors associated with the existence of Axis I psychiatric disorders in patients with chronic idiopathic urticaria (CIU). Method: The study sample was composed of 89 patients with CIU and 64 control subjects. Axis I and Axis II psychiatric disorders were ascertained by means of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition and the Structured Clinical Interview for DSM, Revised Third Edition Personality Disorders, respectively. Results: Of patients with CIU, 44 (49.4%) had at least one Axis I diagnosis, and 40 (44.9%) had at least one personality disorder. The most common Axis I disorder was obsessive-compulsive disorder (25.8%), and the most common Axis II disorder was obsessive-compulsive (30.3%) personality disorder in patients with CIU. Obsessive-compulsive disorder, major depression, obsessive-compulsive and avoidant personality disorders were more prevalent in patient group compared to control group. Obsessive-compulsive and avoidant personality disorders were related to the existence of Axis I disorders in patients with CIU. Conclusion: Psychiatric morbidity seems to be a frequent healthy problem in patients with CIU. (c) 2008 Elsevier Inc. All rights reserved.