Attitudes of healthcare workers (HCWs) toward vaccines are extremely important for increasing vaccination coverage. We conducted a cross-sectional study at the beginning of the fourth COVID-19 vaccination dose campaign among 124 HCWs to evaluate attitudes towards the fourth dose and willingness to get vaccinated. At that time, Israel was the first country to approve the fourth vaccine dose. Most women were unwilling to get the fourth vaccine dose compared to men; 53.9% of physicians were unwilling to get vaccinated compared to 83.3% of nurses and 69% of other HCWs professions. The most frequent concerns regarding the vaccine were its efficacy, benefit, and necessity. The perceived risk and perceived severity of the health risk involved with getting vaccinated with the fourth dose were higher among HCWs who stated that they would not get vaccinated compared to those who were vaccinated or intended to get vaccinated. In contrast, HCWs who were vaccinated with the fourth dose, or those who were planning to get vaccinated, gave higher scores to the perceived benefit of the booster, its advantages, its perceived safety, its ability to protect from severe illness, and the perceived extent of scientific information about the risk associated with the booster. A logistic regression model revealed that perception of the fourth dose's benefits and risk significantly predict the willingness of HCWs to get vaccinated. Willingness to vaccinate their own children, acceptance of a hypothetical annual booster vaccine, and having less severe adverse effects after prior vaccination were also associated with willingness to get the fourth dose. These findings could help policy makers in developing strategies to expand the acceptance and coverage of the COVID-19 booster doses.