All referrals made to the liaison psychiatric service for HIV and AIDS patients over one year were reviewed. ICD–9 and CDC diagnoses were applied to each case at presentation. Sixty HIV-positive patients were assessed, of whom 35 had affective disorder, which was significantly associated with CDC group IV disease (AIDS). Adjustment reaction was seen in nine patients, paranoid states in six, dementia in four, personality changes in four and paranoid schizophrenia in two. CT scans of the brain were performed on 23 of the patients: 17 of these showed abnormalities. The proportion of registered AIDS patients who were referred was five times the proportion of HIV patients.