Hepatitis B and C viral infections are amongst the most critical occupation-related infections in the hospital workplace. This study assesses the determinants of uptake and completion of hepatitis B vaccine amongst health care personnel (HCP) in a tertiary health facility in South-South, Nigeria. This study employs a descriptive cross-sectional study design, and data were collected using a quantitative method. Pre-tested, semi-structured interviewer-administered questionnaires were administered to 280 HCP. The IBM SPSS version 21.0 was used for data analysis. About half of HCP had received the first dose of the hepatitis B vaccine, with less than half of that number completing the third dose. It is significantly higher amongst the core healthcare professionals than the non-healthcare professionals. There is a high drop-out rate in the hepatitis B vaccination process which was more amongst the non-clinical group than the clinical. The short duration of work (1-5 years) is a significant predictor of initiation of the vaccination process, while good knowledge of hepatitis B and C viruses was a strong predictor for complete uptake. This study reveals a fair uptake of the first dose of hepatitis B vaccine amongst HCP with a high drop-out rate and a concomitant low completion of the vaccine course amongst respondents. Priority should be given to ensure planned programmes that will help enhance optimal uptake of hepatitis B vaccine amongst HCP.