Superinfections with various bacteria exacerbate the symptoms of coronavirus disease 2019 (COVID-19). Bilateral peritonsillar abscesses are rare and could be fatal, and their occurrence after COVID-19 has not been reported. A 20-year-old woman visited our hospital with a sore throat. The patient was diagnosed with COVID-19 infection, with no tonsillitis or peritonsillar abscess. Five days later, she returned to our department because of the deterioration of a sore throat. The patient was diagnosed with bilateral peritonsillar abscesses and admitted to the hospital for abscess drainage and antibiotics, which relieved her symptoms in seven days. Although a sore throat is a common symptom of COVID-19, clinicians should be aware of the possibility of other upper airway diseases, including bilateral peritonsillar abscess, during COVID-19 treatment.