Factors predictive of mortality in patients with AIDS and Pneumocystis carinii pneumonia (PCP) were identified before the introduction of adjunctive steroids, but they have not been reevaluated since. Because PCP still occurs in AIDS, remaining fatal in some cases, we conducted a multivariate analysis of factors predicting mortality in patients with HIV-positive PCP managed from 1990 to 1995, i.e., after the consensus conference on the use of adjunctive steroids. The predictive value of clinical, laboratory, and bronchoalveolar lavage (BAL) data at admission and during the course of PCP was studied retrospectively using multivariate methods, in 144 patients with AIDS. Overall mortality was 21.5%. The univariate analysis identified seven factors predictive of 90-d mortality: Pa(O(2)) on room air < 60 mm Hg, lactate dehydrogenase > 1,000 IU, albuminemia < 30 g/L, BAL neutrophilia > 10%, nosocomial infection, pneumothorax, and a need for mechanical ventilation. Four of these factors were independently associated with 90-d mortality in the multivariate analysis; among them, two were evaluable at admission, namely, Pa(O(2)) < 60 mm Hg on room air and BAL neutrophilia > 10%, and two during hospitalization, namely, the development of pneumothorax and a need for mechanical ventilation. Moreover, BAL neutrophilia was correlated to occurrence of pneumothorax and a need for mechanical ventilation. In the era of adjunctive steroid use, AIDS-related PCP remains fairly common. Two independent factors evaluable at admission, Pa(O(2)) on room air and BAL neutrophilia, are predictive of death.