We describe the cases of two individuals with advanced AIDS who sought treatment for rapidly progressive respiratory failure due to T gondii pneumonia. The first patient responded to specific therapy after an early diagnosis but died 2 months later of bacterial sepsis. In the second case, the diagnosis was made at autopsy. This led to a meticulous retrospective review of the original slides of material obtained from BAL. T gondii tachyzoites not previously identified during the initial analysis of the slides were seen on both GIE and PAP stains. Neither of our severely immunocompromised patients had evidence of central nervous system involvement. Even though we cannot exclude dissemination to other organs, a progressive pneumonitis mimicking a classic P carinii infection was the primary presentation. Trophozoites were identified by BAL in both cases, underscoring the diagnostic potential of this minimally invasive procedure.