Title: Seroprevalence and infectitvity of hepatitis B virus among pregnant women: A comparative study of primary, secondary, and tertiary health institutions in Ibadan, Oyo state, Nigeria. Aim: To comparatively evaluate the prevalence of hepatitis B surface antigenaemia and infectivity status among pregnant women attending antenatal clinics in primary, secondary, and tertiary health institutions in Ibadan, Oyo State, Nigeria. Specific Objectives: 1. To assess the knowledge of hepatitis B infection and vaccination among pregnant women attending antenatal clinics at various health care levels within Ibadan, Oyo state, Nigeria. 2. To determine their previous access to hepatitis B screening and vaccination services. 3. To determine the seroprevalence and infectivity of hepatitis B infection among these pregnant women in each level of health care. 4. To compare the seropositivity and infectivity status between the various levels of health care. Materials and Methods A total of 643 pregnant women were enrolled. Their serum samples were tested for hepatitis B surface and envelope antigens using full enzyme linked immunosorbent assay (ELISA) kits (Dia. Pro. Diagnostic Bioprobes Sri via Columella no 31-Milano- Italy).