Coronavirus disease 2019 (COVID-19) generally presents with fever, shortness of breath and a sore throat. These symptoms are also common in oral and pharyngeal infections, such as peritonsillar abscess (PA). The present study describes a case of PA and COVID-19 co-infection. Although COVID-19 was initially suspected in the patient due to the presenting symptoms of fever, sore throat, dysgeusia and dysosmia, an oral examination and computed tomography scan detected PA. The patient was conservatively managed with intravenous antibiotics without transoral drainage of the abscess. Anti-COVID-19 medication was not administered as the COVID-19 infection in the patient was not severe. Laboratory findings revealed high levels of leukocytes, C-reactive protein (CRP) and procalcitonin. On the whole, the association between laboratory findings (including leukocyte count, CRP and procalcitonin levels) and bacterial co-infection with COVID-19 remains unclear, and further studies are warranted. Oral examinations and transoral procedures are often avoided due to the high risk of the aerosolisation of COVID-19 viral particles. However, an appropriate evaluation is essential in order to avoid the underdiagnosis of life-threatening bacterial infections that co-exist with COVID-19.