Hepatitis A virus infection (HAV) and diarrhoea share the same epidemiological risk factors and both have a worldwide distribution. The largest burden is seen in developing countries and resource poor environments particularly sub-Saharan Africa. There is a global and regional variation in HAV infection and diarrhoea. HAV infection is associated with hepatitis, which could be fulminant and may cause death in some proportion (0.5-1%). A good understanding of the association between the risk factors of HAV infection and diarrhoea might aid in providing interventions that limit both infections. This cross sectional case-control study was carried out between June 2018 and October 2018, to determine the seroprevalence and predictors of Hepatitis A virus infection in children aged 12-59 months with diarrhoea attending Federal Medical Centre Owerri. Children in this age group who sought care at the Children Out-patient Clinic, Emergency Paediatric Unit and those admitted into the Ward who also met the inclusion criteria were recruited consecutively into the study. Seropositivity of HAV was determined by Enzyme Linked Immunosorbent Assay using DRG® anti-HAV total antibody kits. Data was obtained using an interviewer administered questionnaire and analysis were done using Statistical Package for SocialSciences (SPSS) Version 23.0.