Objective: As coronavirus disease 2019 (COVID-19) rages on, it is a challenging task to balance resources for treatment of COVID-19 and malignancy-based treatment. For the development of optimal strategies, assessing the conditions and constrains in treatment during the COVID-19 pandemic is pertinent. This study reported about a nationwide survey conducted by the Japan Society of Gynecologic Oncology. Methods: We interviewed 265 designated training facilities about the state of their clinical practice from the time period between March and December 2020. We asked the facility doctors in charge to fill a web-based questionnaire. Results: A total of 232 facilities (87.5%) responded. A decrease in the number of outpatient visits was reported, and the major reason attributed was reluctance of patients to visit hospitals rather than facility restrictions. The actual number of surgeries decreased by 3.9%, compared to 2019. There was a significant difference when the variable of “Prefectures operating under special safety precautions” or not was introduced. There was no increase in the rate of advanced stages in the three cancer types studied. However, 34.1% participants perceived COVID-19 affected management and prognosis. Conclusion Refraining from visiting hospitals based on the patient's judgment may be expected to be an issue in the future. No significant decrease in surgeries was observed, and it would seem that there were few forced changes in treatment plans, but “the State of Emergency” had an impact. There was no increase in the rate of advanced cancers, but this will need to be monitored.