ObjectiveTo assess the frequency with which HIV-seropositive patients treated with corticosteroids develop cytomegalovirus (CMV) disease.DesignRetrospective case-controlled study.MethodsAll 130 patients receiving systemic corticosteroids over a 20-month period at the HIV Unit, Westminster Hospital, London, UK were reviewed for the development of clinical CMV disease within 28 days. The incidence of CMV disease in this group was compared with that in a cohort admitted during the same period, which was matched for admission diagnosis, HIV risk group, antiretroviral therapy and CD4 lymphocyte subset count (± 20%) at admission.ResultsEleven of the 130 patients given corticosteroids developed CMV disease within 28 days, compared with two patients in the case-controlled cohort. All patients who developed CMV disease had a CD4 count < 50 x 106/l on admission.ConclusionThe use of corticosteroids in patients with advanced immunosuppression due to HIV infection should be reviewed carefully in view of the possible increased incidence of CMV disease.