Few studies have investigated the influence of the Coronavirus Disease 2019 (COVID-19) pandemic on emer-gency medical service (EMS) systems, especially in areas less affected or unaffected by COVID-19. In this study, we investigated changes in prehospital EMS activity and transport times during the COVID-19 pandemic. All patients transported by EMS in the city of Okayama from March–May 2019 or March–May 2020 were included. Interfacility transports were excluded. The primary outcome was the time from a patient’s first emergency call until hospital arrival (total prehospital time). Secondary outcomes included three segments of total prehospital time: the response time, on-scene time, and transportation time. Total prehospital time and the durations of each segment were compared between corresponding months in 2020 (COVID19-affected) and 2019 (control). The results showed that total prehospital times in April 2020 were significantly higher than those in 2019 (33.8 ± 11.6 vs. 32.2 ± 10.8 min, p < 0.001). Increases in total prehospital time were caused by longer response time (9.3 ± 3.8 vs. 8.7 ± 3.7 min, p < 0.001) and on-scene time (14.4 ± 7.9 vs. 13.5 ± 6.2min, p < 0.001). The COVID-19 pandemic was thus shown to affect EMS and delayed arrival/response even in a minimally affected region. A system to minimize transportation delays should be developed for emerging pandemics.