Objective: To examine the magnitude of isolated anti-HBc and other HBV serological patterns and associated predictors among adults seeking general health check-up at a large health center in Vietnam. Methods: All 564 outpatients seeking general health checkup between January 2016 and December 2016 were asked to undertake HBV surface antigen, surface antibody, IgG and IgM core antibody (anti-HBc total), platelet counts, and liver function testing. An administered questionnaire was used to collect information regarding demography, in-house sources of infection, lifestyle, health condition and treatment, and HBV vaccination. Results: Male gender (P=0.043), age (P=0.000), living in urban areas (P=0.040), HBV vaccination status (P=0.033), and ALT (P=0.040) were associated with isolated anti-HBc. HBV infection was associated with HBV vaccination status (P=0.001), ALT levels (P=0.010), AST levels (P=0.020), and platelet counts (P=0.007). Past/resolved HBV infection was associated with AST levels (P=0.005), ALT levels (P=0.014), and age (P=0.000). Conclusions: Isolated anti-HBc is quite prevalent. Predictors of isolated anti-HBc include male gender, living in rural areas, and HBV non-vaccination. The prevalence of isolated anti-HBc also increases with age. To timely detect occult HBV infection and prevent transmission, anti-HBc testing should be included in the health check-up for high risk individuals and screening program where HBV nucleic acid test is not available. To prevent transmission, clinicians need to pay more attention on those who are at risk of having isolated anti-HBc and closely follow-up patients with isolated anti-HBc and educate them about the prevention of HBV infection.