Introduction: health personnel is one of the main risk groups for infection with Hepatitis B virus, and although there is a vaccine based on recombinant surface antigen of the virus, not all vaccinated individuals reach protective antibody titers. Objective: to establish the relationship between serum titers of anti-Hepatitis B Virus and the number of doses of vaccine against hepatitis B, in staff of the Medical School at Universidad Cooperativa de Colombia, Medellin, in 2011. Materials and methods: a cross-sectional study in a probability sample of 162 people was conducted. The data collection was from primary source. Statistical analysis was made ​​based on proportions, summary measures, parametric and nonparametric statistics. Results: 80% of the study group had protective antibodies, the average antibody titer was 396 mIU/mL, it was statistically associated with the number of doses, and there was no statistical association with sex or age. Conclusion: the protection found against hepatitis B virus was lower than that reported internationally for recombinant vaccines (approximately 90-95% in young adults). This could be attributed to the inclusion of people with incomplete vaccination schedules or poor immune response to the vaccine, such as men, individuals with high body mass index, adulthood, smoking status, and individuals with HLA DR3-DQ2.