0.0001). CONCLUSION: Over the last 18 years, there has been a marked decline in the prevalence of HAV in Saudi children and adolescents. The current low prevalence rates call for strict adherence to vaccination policies in high-risk patients and raises the question of a universal HAV vaccination program. INTRODUCTIONHepatitis A (HAV) is a major health problem worldwide and, like other enteric infectious diseases, is classically an infection of childhood. Although acute infection commonly passes unnoticed, a significant proportion of patients may have fulminant liver failure, especially patients with liver cirrhosis or immune deficiencies. Generally, its prevalence pattern varies from one population to the other and is closely related to the socioeconomic conditions of sanitation and hygiene. An improvement in sanitation and living standards in many areas of the world has caused the epidemiology of HAV to rapidly evolve. As such, with an improvement in living conditions, more clinical cases are being diagnosed owing to the increased age of those susceptible, which is paradoxical to childhood infection where the majority of infections are subclinical [1][2][3][4][5] . The availability of safe and efficacious vaccines against HAV has made it Abstract AIM: To determine the seroprevalence of Hepatitis A (HAV) amongst Saudi children and compare it with previously reported prevalence data from the same population. METHODS: A total of 1357 students were randomly selected between the ages of 16 and 18 years (689 males and 668 females) from three different regions of Saudi Arabia (Madinah, Al-Qaseem, and Aseer) and tested for anti-HAV-IgG. RESULTS: The overall prevalence of anti-HAV-IgG among the study population was 18.6%. There was no difference between males and females but there was a significant difference in the seroprevalence (P = 0.0001) between the three different regions, with Madinah region showing the highest prevalence (27.4%). When classified according to socioeconomic status, lower class students had a prevalence of 36.6%, lower middle class 16.6%, upper middle class 9.6%, and upper class 5.9% (P = 0.0001). Comparing the current study results with those of previous studies in 1989 and 1997 involving the same population, there was a marked reduction in the overall prevalence of HAV