ObjectivesThis study aimed to examine whether and how the COVID-19 pandemic has affected the postponement or cancellation of elective surgeries in Japan.Design and settingA cross-sectional, web-based, self-administered survey was conducted nationwide from August 25 to September 30 2020. We used data from the Japan ‘COVID-19 and Society’ Internet Survey collected by a large internet research agency, Rakuten Insight, which had approximately 2.2 million qualified panellists in 2019.ParticipantsFrom a volunteer sample of 28 000 participants, we extracted data from 3678 participants with planned elective surgeries on any postponement or cancellation of elective surgeries.Outcome measuresThe main outcome measure was any postponement or cancelltion of elective surgeries. In addition, for all respondents, we extracted data on sociodemographic, health-related characteristics, psychological characteristics and prefectural-level residential areas. We used weighted logistic regression approaches to fulfil the study objectives, minimising potential bias relating to web-based surveys.ResultsOf the 3678 participants, 431 (11.72%) reported experiencing postponement or cancellation of their elective surgeries. Notably, the participants living in prefectures where the declaration of the state of emergency was made on 7 April 2020 were significantly more likely to experience postponement or cancellation of elective surgeries than those residing in prefectures with the state of emergency beginning on 16 April 2020 (174 (26.02%) vs 153 (12.15%)).ConclusionsThe proportion of patients whose elective surgery had been postponed was limited during Japan’s first wave of the COVID-19 pandemic, although the declaration of a state of emergency increased the likelihood of postponement. It is imperative to increase awareness of the secondary health effects related to policy intervention in pandemics and other health crises and to use appropriate countermeasures such as standard infectious control measures and triage of surgical patients.