The Structured Clinical Interview for DSM-III-R (SCID and SCID II) was administered to 105 eating disorder in-patients in order to examine rates of comorbid psychiatric disorders and the chronological sequence in which these disorders developed. Eighty-six patients, 81.9% of the sample, had Axis I diagnoses in addition to their eating disorder. Depression, anxiety and substance dependence were the most common comorbid diagnoses. Anorexic restrictors were significantly more likely than bulimics (all subtypes) to develop their eating disorder before other Axis I comorbid conditions. Personality disorders were common among the subjects; 69% met criteria for at least one personality disorder diagnosis. Of the 72 patients with personality disorders, 93% also had Axis I comorbidity. Patients with at least one personality disorder were significantly more likely to have an affective disorder or substance dependence than those with no personality disorder.