The incidence of infection by Hepatitis A virus shows regional variation being highest in developing countries. Determination of age specific Hepatitis A virus (HAV) seroprevalence and the associated risk factors would help better plan for national preventive strategies including vaccination. We carried out a cross-sectional study on 300 children from Nairobi city, Kenya during the years 2003-2004. The age range of the children was 2 - 14 years and were from low and high socioeconomic status (SES) families. The indicators of SES included employment status, residence, number of children per patient’s household, parents’ level of education and source of drinking water. SES was encoded and analysed using Statistical Program for Social Sciences (SSPS) version 16.0. Seroprevalence increased significantly with advancing age. Seropositivity of HAV antibodies was significantly higher among children of low SES, 77.6% by the age of 14 years compared to children of high SES, 38.9% by the same age. Crowded household and parental education were significantly associated with high seropositivity and seronegativity respectively. There is significant rate of seronegativity amongst the studied population especially those from richer backgrounds making them more susceptible to severe infection in future with concomitant complications. We propose that revision of national vaccination program should be considered to include Hepatitis A vaccination
