The only confirmed outbreak of acute hemorrhagic conjunctivitis in the continental United States during 1982 occurred in Brainerd, Minnesota. The disease first appeared in a 27-year-old woman during a trip to Tahiti. The patient's two daughters (8 months old and 3 years old) developed mild conjunctivitis two days later. Although the symptoms of all three had completely resolved before they arrived in Brainerd, illness compatible with acute hemorrhagic conjunctivitis developed in five other individuals who shared a house with them there. Symptoms appeared within two days in four of the five and within three days in the fifth. All five had high neutralizing antibody titers to enterovirus 70 (1:128, 1:32, 1:32, 1:128, and 1:256) and one had high antibody titers to coxsackievirus A24 which may cause similar symptoms (< 1:4 in all cases). The symptoms resolved without sequelae in all five patients within five days. These cases demonstrated that a person who is no longer symptomatic can still infect others and that an infected person can transmit enterovirus 70 for at least eight days after the onset of symptoms.