During a seven-year survey of acute symptomatic viral hepatitis in Padua (Northern Italy), the epidemiological features of hepatitis A were evaluated in 207 consecutive patients (120 males, mean age 22.7 +/- 11.4 years). The annual attack rate of the disease decreased significantly (p less than 0.05) between 1978 and 1979 (0.11/1000 inhabitants) and 1981 and 1984 (0.04-0.03/1000 inhabitants), mainly due to its declining prevalence in the pediatric age. In parallel with the shifting of hepatitis A towards adulthood, single sources of infection, mainly associated with adult life-style such as foreign travel and raw shellfish ingestion, have become more and more prominent. The spread of drug abuse has not influenced the epidemiology of hepatitis A in our area.