The uptake of COVID-19 vaccination among cancer patients at the Ocean Road Cancer Institute (ORCI) in Dar es Salaam, Tanzania, was assessed in a study conducted in September 2022. The study aimed to evaluate vaccination coverage and associated factors, considering the vulnerability of cancer patients. The research design was a cross-sectional analytical study, employing a multistage sampling approach for quantitative data collection and purposeful sampling for qualitative data. The study included 479 cancer patients, with a focus on their socio-demographic, clinical, and Health Belief Model (HBM) variables. The results revealed that 58.2% of participants were vaccinated against COVID-19, with a higher proportion of females (79.5%) among the vaccinated group. After adjusting for other variables, factors significantly associated with vaccine uptake included having secondary school education or higher education (Adjusted odds ratio [aOR] 2.26, 95% CI 1.20–4.27; p = 0.011), positive perception of the COVID-19 vaccine (aOR 8.86, 95% CI 2.84–32.2; p < 0.001), and perceived severity of COVID-19 (aOR 0.56, 95% CI 0.36–0.87; p = 0.010). Qualitative findings suggested that individuals' beliefs, perceptions, and external factors influence their decision to vaccinate. The study concluded that higher education, positive vaccine perception, and perceived disease severity were significant factors in increasing COVID-19 vaccination uptake among cancer patients at ORCI. Public health interventions should consider these factors to tailor communication efforts effectively.
