The clinical, epidemiological and virological findings of the 1980 epidemic of acute conjunctivitis were described. Enterovirus 70 was isolated from 7 (35%) of 20 eye swabs submitted for virus isolation, and the paired sera of eight patients showed a four-fold or greater rise in neutralising antibody titre to Enterovirus 70. The disease mainly affected children and young adults of all ethnic groups. Most of the cases contracted the infection at home. The mean secondary attack rate was 72.6% and the mean incubation period, four days. The clinical features were similar to the 1970 and 1975 epidemics caused by Coxsackievirus A24. Subconjunctival haemorrhage was observed in 10% of the cases. Most of the cases recovered spontaneously within a week. Transmission of infection within the home was either indirect, probably through fomites contaminated with eye or respiratory discharges of cases, or direct, through intimate person-to-person contact. During outbreaks, health education on simple personal hygiene should be highlighted.