With the planned COVID-19 vaccine, vaccine hesitation is a great challenge, particularly for healthcare professionals. In this study, we examined the acceptance of the COVID-19 vaccine by health care workers, their concerns about it, and the reasons that might prevent them from getting vaccinated. We conducted a cross-sectional study using an anonymous online survey from December 25, 2020, to January 6, 2021. The questionnaire consisted of demographic characteristics (age, gender, profession, sector, medical history, and general health), COVID-19 related knowledge, and personal history of influenza vaccination. The intention to get the vaccine once it is available was directly asked, and attitudes towards the diseases and the vaccine were studied using a four-point Likert scale statement based on the health belief model's constructs. The study included 1159 HCWs; 62.9% were females, and 52.5% were between the ages of 30-49 years. The intention to get vaccinated was only 37.8% [95%CI: 35.0%-40.6%], while 31.5% were undecided, and 30.7% planned to refuse it. Higher levels of intention were reported among males (OR; 2.7, 95%CI: 2.0-3.7), younger ages (OR 1.7, 95%CI: 1.1-2.8), physicians (OR; 2.9, 95%CI: 2.0-4.0), HCWs at non-governmental settings (OR; 1.4, 95%CI: 1.1-1.9), those who previously received the influenza vaccine (OR 4.0, 95%CI: 2.3-7.1), and those who had higher COVID-19 related knowledge (OR; 1.7, 95%CI: 2.3-7.1). In conclusion, vaccine acceptance among HCWs was much lower than expected, which would greatly diminish the role of vaccination in reducing the burden of the COVID-19 pandemic throughout the community. Copyright © 2021 Elsevier Inc. All rights reserved.