PURPOSE To evaluate stress levels among the health care workers (HCWs) of the radiation oncology community in Asian countries. METHODS HCWs of the radiation oncology departments from 29 tertiary cancer care centers of Bangladesh, India, Indonesia and Nepal were studied from May 2020 to July 2020. A total of 758 eligible HCWs were identified. The 7-Item Generalized Anxiety Disorder, 9-Item Patient Health Questionnaire, and 22-Item Impact of Events Scale-Revised were used for assessing anxiety, depression, and post-traumatic stress disorder. Univariate and multivariate analysis was done to identify the causative factors affecting mental health. RESULTS A total of 758 participants from 794 HCWs were analyzed. The median age was 31 years (IQR, 27-28). The incidence of moderate to severe levels of anxiety, depression, and stress was 34.8%, 31.2%, and 18.2%, respectively. Severe personal concerns were noticed by 60.9% of the staff. On multivariate analysis, the presence of commonly reported symptoms of COVID-19 during the previous 2 weeks, contact history (harzard ratio [HR], 2.04; CI, 1.15 to 3.63), and compliance with precautionary measures (HR, 1.69; CI, 1.19 to 2.45) for COVID-19 significantly predicted for increasing anxiety (HR, 2.67; CI, 1.93 to 3.70), depression (HR, 3.38; CI 2.36 to 4.84), and stress (HR, 2.89; CI, 1.88 to 4.43) (P,.001). A significant regional variation was also noticed for anxiety, stress, and personal concerns. CONCLUSION This survey conducted during the COVID-19 pandemic revealed that a significant proportion of HCWs in the radiation oncology community experiences moderate to severe levels of anxiety, depression, and stress. This trend is alarming and it is important to identify and intervene at the right time to improve the mental health of HCWs to avoid any long-term impacts.