In 2020, there was a decrease in the number of mumps cases compared to the previous year. The lower incidence may have been the result of a reduction in mumps virus transmission due to a change in population health behavior during the COVID-19 pandemic. Due to the epidemiological threat, the functioning of nurseries, kindergartens and schools was also temporarily suspended, which resulted in a reduction in the incidence of mumps in younger age groups, which are the main group of patients.