A retrospective case-notes audit of 359 HIV-1-infected adult patients with first-episode laboratory-confirmed Pneumocystis jirovecii pneumonia treated with co-trimoxazole (from 1987 adjuvant steroids were used if PaO(2) <9.3 kPa) showed that only 230/359 (64%) patients completed treatment; 104 (29%) patients had treatment-limiting toxicity; rash occurred in 4/60 (6.7%) patients in 1985-1988 and in 15/47 (31.9%) in 2005-2008. Twenty-five patients (7%) failed co-trimoxazole treatment. Overall mortality was 13.6% (49/359); mortality among patients who failed co-trimoxazole treatment was 48% (12/25) and by contrast mortality was 4.8% (5/104) among patients with treatment-limiting toxicity.