This study investigated lifetime and current rates of axis I diagnoses and the personality traits of neuroticism and extraversion in patients receiving complementary medical care in the United Kingdom and United States. Eighty-three patients were interviewed by means of the Structured Clinical Interview for DSM-III-R, and 78 completed the Eysenck Personality Inventory (EPI). Subjects were drawn from the Royal London Homoeopathic Hospital (n = 50) and a holistic family practice in North Carolina (n = 33). High rates of lifetime (68.7%) and current (39.8%) axis I disorders were found, with no substantial differences between the groups, apart from lifetime posttraumatic stress disorder and current social phobia, which were higher in the US sample. The subjects were more introverted but not more neurotic as compared against normative population data with the EPI. The subjects were predominantly older women. We conclude that psychiatrists may need to be aware that patients with depressive or anxiety disorders are likely to seek out complementary treatments for a wide range of medical problems, and should inquire as to use of these in their patients. They may also need to cultivate greater awareness of the health beliefs of such patients.