A longitudinal survey (February 1984 - January 1985) on the incidence of acute diarrhea episodes in a sample of 8,164 children (aged 0-12 years) living in southeastern Sicily was carried out by means of weekly telephone interviews with doctors practising in the territory. The incidence rate was 0.479 (0.472-0.485 95% C.I.) per child per year and the frequency of episodes was significantly higher (p less than 0.001) in children aged 0-4 years (0.86). Diarrhea was more frequent in industrial areas than in rural ones, and almost half (45.1%) of the total episodes had a mild course. No death from diarrhea occurred and admission to hospital was reported for 8.4% of all cases.