To determine new strategies for complete coverage of hepatitis B virus (HBV) vaccination, every country needs to take into concern factors of infection transmission in its own region. Aims: The aim of this study was to investigate the seroprevalence of hepatitis B among all age groups in northern Turkey using HBsAg and anti-HBs serological markers. Materials and Methods: The laboratory records of a total of 101648 patients of all ages attending a tertiary level hospital in Samsun, a Black Sea coastal city, between January 2014 and May 2016 were evaluated retrospectively. Results: HBsAg and anti-HBs seropositivity was found to be 4% and 38.3%, respectively. There was a significant difference between HBsAg (chi(2) = 209.08; P = 0.00), anti-HBs (chi(2) = 124.12; P = 0.00) seropositivity, and immunization status. Although we found a statically difference between men and women (chi(2) = 32.2 P = 0.00) for HBsAg seropositivity, there was no significant difference for anti-HBs (P = 0.22). In 1998, the universal infant immunization program changed the HBV epidemiology in Turkey, and resulted in an apparent trend towards reduced disease levels. However, prevalence of HBV infection is still high in adolescent and young adults. Conclusions: Therefore, a catch-up immunization program, education, and follow-up policy for these groups, in addition to routine infant immunization, will decrease the HBV infection rate, reducing morbidity and mortality rates, and will help to reduce hepatitis B transmission in Turkey.