The prevalence of antibodies to hepatitis A virus was assessed in a Dutch nationwide sample (n = 7367). A questionnaire was used to study the association with various sociodemographic characteristics. Overall, 33.8% (95% CI 31.6-36%) of the population had hepatitis A antibodies. The seroprevalence was less than 10% in people under 35; it increased from 25% at 35 years to 85% at 79 years. For those 15-49 years of age, Turks (90.9%) and Moroccans (95.8%) had greater seroprevalence than autochthonous Dutch (20.2%) and other Western people (25%). Low or middle socio-economic status, as indicated by the highest educational level achieved, was associated with greater seroprevalence, independently of age and reported immunization (OR 2.11 and 1.45; 95% CI 1.67-2.67 and 1.11-1.89, respectively). These data suggest autochthonous Dutch and other Westerners born after World War II were exposed to hepatitis A during childhood less frequently than older birth cohorts. Thus, more susceptibility is likely in the coming decades. Since this means a greater risk of outbreaks in future years, and since morbidity and mortality are more frequent in older persons, studying the cost effectiveness of selective and general vaccination might be worthwhile.