The human rhinovirus (HRV) is generally considered as the common cold and its mild symptoms\' main cause. However, HRV are also implicated in severe respiratory infections. This study reports on a nosocomial outbreak of bronchitis and pneumonia caused by HRV in a hospital during the COVID-19 epidemic in September 2022 in Gunma Prefecture, Japan. Patients continued to become infected for 9 days. During this outbreak, all 15 residents had respiratory symptoms, and HRV-A was detected in 12 of the 12 samples and phylogenetic analysis showed that it was classified into HRV-A type 61. HRV and COVID-19 or other respiratory infections cannot be differentiated from clinical symptoms; therefore, a surveillance system to monitor them may be needed.