Nasal swab tests are widely used to screen for coronavirus disease 2019 (COVID-19). Pain, discomfort, and the urge to sneeze are the most common complications of this screening method. We report a case of a 55-year-old female patient with beta-thalassemia major suffering from a nasal septal abscess (NSA) as a complication of a COVID-19 nasal swab test. Following the test, the patient only had mild nasal congestion. However, three days later, her clinical condition deteriorated, and she developed fever, and her level of consciousness decreased to lethargy and drowsiness. Physical examinations revealed a bilateral nasal abscess. She underwent surgical intervention, and the abscess was removed. For the first time in Iran, a case of NSA after a COVID-19 nasal swab test is reported. It is strongly recommended to exercise caution while performing nasal swab tests, especially in the elderly and patients at risk of bleeding or hemoglobinopathy.