Eighty initial episodes of HIV-associated Pneumocystis carinii pneumonia (PCP) diagnosed at Bordeaux hospital between 1985 and 1993 are reported (57 were men and 23 women). PCP revealed HIV infection in 29 patients (36%). Others cases were patients with poor medical follow up (10%), with a CD4+ lymphocyte count above 200/mm3 at last follow-up (9%), non compliant with PCP prophylaxis (9%), or using aerolized pentamidine (AP+) (20%). The main clinical symptoms were fever (90%), dyspnea (68%), non productive (63%) and productive (17%) cough. Radiographic infiltrates were purely interstitial (59%), acinar and interstitial (25%), purely acinar (5%) and absent (11%). Thirty-eight percent of AP+ had upper lobe preferential involvement and 13% a pleural effusion. In all cases, Pneumocystis carinii was detected in bronchoalveolar lavage. Extrapulmonary localizations of pneumocystosis were noticed (eye, liver, spleen, ascitis) in two AP+. Mean CD4+ count was 54/mm3 in patients not having received aerolized pentamidine (AP-) and 22/mm3 in AP+. P24 antigenemia was positive in 53% (AP-) and 88% (AP+). PaO2 LDH and albuminemia were similar in both groups. Antimicrobial therapy (Cotrimoxazole in 91% of the cases) was combined with corticosteroids in 45% and mechanic ventilation in 19%. After 30 days of follow-up, 17 deaths were observed (21%) and 14 attributed to PCP: mortality was worse in AP+ (31%) than in AP- (19%). The main conclusions of our study are the followings: HIV related PCP is still in 1995 frequent and severe; atypical features should not rule out diagnosis; preventive measures are neither sufficient nor efficient. PCP remains in 1995 a priority in HIV related public health and therapeutical research.