Since the beginning of the AIDS epidemic, Cryptosporidium has emerged as a pathogen responsible for diarrhea in humans. Cryptosporidiosis confined to the respiratory tract has been documented only rarely in humans. An HIV-infected patient is described here, who developed pulmonary and intestinal cryptosporidiosis. Lung involvement was proven by biopsy, which also revealed bronchiolitis but no other pathogens. The patient died of respiratory failure 2 months after the onset of respiratory symptoms.