Background <p>We aimed to estimate the incidence rate of rotavirus-associated diarrhea in Pudong New Area, Shanghai, China, from 2018 to 2022.</p> Methods <p>Data from the hospital information systems of eight sentinel hospitals and the Healthcare Utilization and Attitudes Survey were used to calculate the incidence rate of rotavirus-associated diarrhea in Monte Carlo simulation.</p> Results <p>The findings revealed a decline in the positivity rate of rotavirus among medically-attended patients with diarrhea, from 13.5% (95% confidence interval [CI]: 12.0–15.0) in 2018 to 5.2% (95% CI: 4.2–6.2) in 2022. The incidence rate of rotavirus-associated diarrhea decreased from 60.5 cases per 1000 person-years (95% CI: 43.4–79.4) during the period 2018–2019 to 10.3 cases per 1000 person-years (95% CI: 7.3–13.9) during the period 2020–2022. A marked decline in the incidence rate of rotavirus-associated diarrhea was observed in community-dwelling populations during the period 2020–2022, compared with the pre-pandemic period of 2018–2019.</p> Conclusion <p>We evaluated the positivity rates of rotavirus and incidence rate of rotavirus-associated diarrhea in Pudong New Area, thereby providing valuable data to clarify the actual disease burden of rotavirus-associated diarrhea.</p> Clinical trial <p>Not applicable.</p>