Introduction: High COVID-19 vaccination acceptance rates and medical trainees' coverage as future health care providers is essential to be accomplished. Aim of Work: to assess the level of COVID-19 vaccine hesitancy status and to detect the motivators and barriers that may affect it among medical trainees. Materials and Methods: A cross-sectional study was conducted among medical trainees in different universities, Egypt. Data was collected via online questionnaire submitted in social media groups during August to November 2021 from 1008 medical trainees representing different governmental and private universities. Results: Most of trainees (79.2%) perceived that they may catch the COVID-19 infection during their training, 31.9% had vaccination hesitancy, and only 40 trainees refused the vaccine. Almost half of hesitant trainees were worried regarding the vaccine's infectiveness in transmitting or preventing infection (50.6%) and side effects (66.8%). The most important motivator was that vaccination decreases the severity of infection (88.9%) among acceptance group. The predictors of acceptance/hesitancy status are vaccine is important for face to face contact (OR: 1.60; p=0.038), and to reduce severity of COVID-19 infection (OR: 2.86; p=0.005), vaccine should be mandatory to travel abroad (OR: 2.3; p=0.016), and vaccine should be mandatory administrated for all (OR: 4.10; p=0.000).Conclusion and Recommendations: More than one third of medical trainees had vaccination hesitancy. Decrease the severity of infection is the most important motivator, the predictors of acceptance/hesitancy status among medical trainees are; vaccine is important for face to face contact, to reduce the severity of COVID-19 infection and vaccine should be mandatory to travel abroad. Health authorities and decision-makers should cooperate with each other and work hard to lessen hesitancy and to promote vaccination awareness that helps to improve COVID-19 vaccines acceptanc.