OBJECTIVE: To recognize the clinical features of the enterovirus 71 (EV71) infection with pulmonary edema or pulmonary hemorrhage as a fulminant and often fatal illness. METHODS: We retrospectively reviewed the medical records of the three cases with EV71 infection for clinical manifestation, laboratory data, medications, outcome etc. RESULTS: All the cases were infants and they all died. These infants had no skin or mucosal lesions, however, they had sudden onset of cyanosis and tachypnea 1 to 2 days after the onset of the febrile disease with vomiting. All these 3 cases were misdiagnosed and were treated for shock on admission. Pulmonary hemorrhage was not considered in any of the cases on admission. All the cases received tracheal intubation when foamy secretions were discharged from mouth and nose of the patients and notable cyanosis was noted. After intubation, all had pink foamy fluid flew out from the endotracheal tube. The patients had hyperglycemia and limb weakness, two had tachycardia, and hypertension was found in one case. Chest X-ray showed bilateral or unilateral widespread air space opacity, but the cardiac size and shape were normal. All the patients had leucocytosis. EV71 infection was confirmed by detection of specific sequences of the virus in throat swab and tracheal secretions samples and in one case in cerebrospinal fluid sample. CONCLUSION: Pulmonary edema or pulmonary hemorrhage occurred in the 3 cases with EV71-infected infants. The initial presentation was often nonspecific with fever and vomiting, and sudden appearances of cyanosis, tachypnea, tachycardia, hypertension or hypotension, limb weakness may suggest pulmonary edema or hemorrhage. Excessive fluid resuscitation may deteriorate the illness, on the contrary, fluid restriction and inotropic agents, and early intubation with positive pressure mechanical ventilation may be the proper treatment.