At the University Hospital, Kuala Lumpur, Malaysia, nine patients with systemic lupus erythematosus (SLE) were treated for Pneumocystis carinii pneumonia (PCP) between January 1987 and December 1988. When they developed PCP all the patients' SLE disease course was active and eight of them were on prednisolone. Four of these eight patients were also receiving cyclophosphamide. Patients who were on more intensive immunosuppressive therapy were found to develop more severe PCP. All the patients except one were treated with high-dose cotrimoxazole. Four patients responded to antipneumocystis treatment and survived, while PCP was responsible for the death of the five non-survivors.