The aim of the study was to determine the prevalence of personality disorders in the early course of fi rst-episode psychosis and their likely presence in the premorbid period. Fifty-fi ve patients were enrolled at baseline and premorbid function was evaluated by the Premorbid Adjustment Scale. Thirty-three of these of the patients were assessed at two-year follow-up for comorbid personality disorders by the Structured Clinical Interview for DSM-IV Personality Disorders and by the self-report instrument Millon Clinical Multiaxial Inventory-II. Half of the patients met the criteria of two or more personality disorders, while one-third of the patients did not fulfi l the criteria for any personality disorder. The schizoid and the avoidant were the most frequent per- sonality disorders and both were associated with social withdrawal during childhood and adolescence. The limitation of the study is the small sample, the retrospective assessment and a 40% attrition rate. The strengths are that it is a clinical epidemiological sample of fi rst-episode psychotic patients and that different but compli- mentary measures of the personality disorders were used. Copyright © 2008 John Wiley & Sons, Ltd. Introduction