Background: This study aimed to investigate the changes in the incidence of shoulder trauma and surgery 1 year after the outbreak of coronavirus disease 2019 (COVID-19) with social restriction compared with 1 year before the pandemic. Methods: Patients managed in our orthopedic trauma center between February 18, 2020, and February 17, 2021 (COVID-19 period) for shoulder trauma were compared with patients managed for the same duration a year ago (non–COVID-19 period; February 18, 2019, to February 17, 2020). The incidence of shoulder trauma, surgery, and mechanism of injury were compared between these periods. Results: The total number of shoulder trauma cases was lower in the COVID-19 period than in the non–COVID-19 period, although the difference was not significant (160 vs. 180 cases, p = 0.278). In addition, traumatic shoulder surgeries decreased during the COVID-19 period (57 vs. 69 cases, p = 0.285). The incidence of shoulder trauma according to four diagnostic classifications (contusion, sprain/subluxation, fracture, and dislocation) and fracture/dislocation types did not differ between the periods. During the COVID-19 period, accidental falls outdoors (45 vs. 67, p = 0.038) and sports-related injuries (15 vs. 29, p = 0.035) significantly decreased, but accidental falls at home (52 vs. 37, p = 0.112) increased compared with those during the non–COVID-19 period, although the difference was not significant. The monthly incidence of shoulder trauma decreased 2 months after the first outbreak (significant in March, p = 0.019), then steadily increased and significantly decreased during the second outbreak (August, p = 0.012).However, the third outbreak (December, p = 0.077) had little effect on the incidence of shoulder trauma. The number of monthly traumatic shoulder surgeries showed a similar pattern to the monthly incidence of shoulder trauma. Conclusions During the COVID-19 pandemic, annual shoulder trauma cases and surgeries decreased compared to those in the non–COVID-19 period, even though the difference was insignificant. The incidence of shoulder trauma and surgery was significantly reduced in the early COVID-19 period; however, the effect of the pandemic on orthopedic trauma practice was minimal after approximately half a year. Decreases in falls outdoors and sports-related injuries, but an increase in falls at home, were observed during the COVID-19 pandemic.