Background: Since Health care workers (HCWs) are at high occupational risk for COVID-19, they are prioritized for immunization. This study aims to assess the acceptance rate of COVID-19 vaccine among HCWs and to identify its determinants.Methodology: A web-based cross-sectional study was conducted over the period extending from 10 to 31 December 2020 among Lebanese HCWs. The Health Belief Model (HBM) was used as theoretical framework. Descriptive statistics were reported using frequency with percentages for categorical variables. Bivariate and multivariable logistic regression were carried out to identify the factors associated with the acceptance of COVID-19 vaccine. Adjusted odds ratio and their 95% confidence intervals were reported. The level of statistical significance was set at a p-value < 0.05. Results: A total of 1800 HCWs have completed the survey. Around half of them were frontliners aged between (30-49) years old. About two third (67.33%) have received their influenza vaccine this year. The acceptance rate of COVID-19 vaccine among surveyed HCWs was 58%. Being a male (aOR=1.988, 95% CI (1.411-2.801)), working in the frontline (aOR=1.610, 95% CI (1.173-2.209), and having received influenza vaccination this year (aOR=1.378, 95% CI(0.990-1.916))were significantly associated with higher COVID-19 vaccine acceptance. However, living in rural area (aOR=0.606, 95%CI (0.440-0.836)), personal history of COVID-19 (aOR=0.695, 95%CI (0.470-1.029), novelty of vaccine (aOR=0.424, 95% CI (0.255-0.706)), side effects (aOR=0.413, 95%CI (0.234-0.731), reliability of manufacturer (aOR=0.434, 95% CI (0.297-0.633) and vaccine frequency (aOR=0.580, 95% CI (0.403-0.836) were negatively associated with the willingness to take it. Remarkably, limited availability (aOR=2.161, 95% CI(1.461-3.197) and accessibility (aOR=1.680, 95% CI (1.141-2.474) to the vaccine were also positively associated to its uptake. Similarly, HCWs who perceived vaccine benefits were more likely to get vaccinated (aOR=11.048, 95% CI (7.993-15.269)). With regards to cues of action, having reliable and adequate information regarding the vaccine (aOR=1.979, 95% CI (1.361-2.878)), recommendation by health authorities (aOR=1.976, 95% CI(1.343-2.908)) or health facilities (aOR=2.684, 95% CI(1.804-3.994)) were positively linked to vaccine acceptance, whilst recommendation by family members (aOR=0.479, 95% CI(0.283-0.811)) was negatively related to it. Conclusion:Pointing out the factors driving moderate vaccine acceptance among HCWs via targeting messages addressing key concerns would be required to reach higher vaccination rate.