The association of Pneumocystis carinii pneumonia and cytomegalovirus infection in apparently healthy intravenous drug abusers or homosexual males recently has been described. Two patients with this syndrome were seen recently at our institution. Bronchoalveolar lavage samples from these two patients, taken at the time of bronchoscopy, were analyzed. In both patients a significant increase in inflammatory cells (polymorphonuclear cells) and evidence for polyclonal B cell activation, as measured by a reverse hemolytic plaque assay was seen compared to normal persons (p less than 0.01 both comparisons). IgM and IgG anti-Pneumocystis carinii antibody titers were elevated in the lavage fluid of one patient each. One patient, originally diagnosed as having "Hamman-Rich Syndrome," demonstrated unequivocal chest X-ray improvement with prednisone therapy alone. These observations suggest that the lungs of these two patients were the site of an intense inflammatory response, which was not reflected in studies with peripheral blood.