BACKGROUND SARS-CoV-2 caused a worldwide pandemic, and mRNA vaccines against the SARS-CoV-2 spike protein were developed to avoid SARS-CoV-2 infection. Short-term adverse events, such as fever, malaise, body aches, and headaches, develop within a few days following COVID-19 vaccination. Those adverse events are common and widely known as transient reactions. Recently, an association with COVID-19 vaccine as an inducer of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis has been noted. Furthermore, a relationship between COVID-19 vaccination and the development of autoimmune diseases has been reported and termed rheumatoid immune-mediated inflammatory disease. However, the mechanisms of the immune response following COVID-19 vaccination in relation to ANCA-associated vasculitis development remain unclear. CASE REPORT We report a case of a female patient who developed otitis media with ANCA-associated vasculitis following the third dose of COVID-19 mRNA vaccination. A 74-year-old woman presented with bilateral hearing loss and malaise for 1 month after COVID-19 vaccination. Serum myeloperoxidase-ANCA levels were confirmed to be elevated, and pure-tone audiometry revealed moderate bilateral mixed hearing loss. Treatment with steroids and rituximab led to recovery of hearing loss and a reduction in myeloperoxidase-ANCA titre. CONCLUSIONS The pathogenesis of adverse events following COVID-19 vaccination are still unclear. This report has indicated that ANCA-associated vasculitis can be related to COVID-19 mRNA vaccines. As our knowledge of autoimmune disease developing after COVID-19 vaccination is still in the accumulation phase, it is relevant to amass such case reports and use them for assistance in diagnosis in the future.