Background: During the COVID-19 pandemic telemedicine became an attractive alternative to in person appointments. The role of telemedicine in patients who undergo frequent on site treatment, such as radiation therapy, is unclear. The purpose of this study was to examine telemedicine use, physician satisfaction and barriers to continued use in radiation oncology. Methods: An anonymous, electronic survey was distributed to radiation oncologists internationally. Participants described demographic and practice characteristics and a 5 point Likert scale assessed provider satisfaction, ease of use and overall utility of telemedicine. Analyses include descriptive statistics and subgroup comparisons using Chi-square and Fisher’s exact test. Results: 232/5343 (4.3%) completed the survey, 63.8% of whom were male, 52.6% age 50 or younger and 78.0% from the United States (U.S.). Only 14.2% used Telemedicine previously, which increased to 93.1% during COVID-19. Amongst all telemedicine users, usage rates were 77.9% for initial consultations, 97.2% for follow-up visits, and 35.9% for on-treatment visits. 69.8% report that <25% of patients requiring treatment experienced delays due to COVID-19. Most conducted appointments from the workplace, with 40.1% also doing so from home. Satisfaction was high at 73.8%, perceived usefulness was 76.9% and 81.5% hope to continue using telemedicine after the pandemic. However, 82.4% had concerns with the inability to examine patients. Although 82.1 % believed that telemedicine would improve patient access to health care services overall, 63.0% were concerned with patient ability to access required technology. 49.5% had concerns regarding continued billing/reimbursement; less commonly at government centers (18.8%) compared to academic/satellite facilities (52.7%) and free-standing centers/community hospitals (50.7%), p=0.039 for both comparisons. These concerns were also significantly higher amongst US physicians (53.2% vs 34.9%, p=0.048). Conclusions: Widespread adoption of telemedicine by radiation oncologists occurred during COVID-19 with high rates of satisfaction and interest in continued use. Sustained reimbursement for telemedicine services is a significant concern, particularly in the US and outside of government facilities.