The classic Osborn wave in the form of characteristic changes at the depolarization end or ventricular repolarization beginning is more often associated with hypothermia (body temperature below 35,6° C). Some researchers have noticed Osborn wave at normal body temperature, various pathological conditions and diseases: hypercalcemia, myocardial ischemia, postoperative pericarditis, with central nervous system, etc. We presented a case report of a 72-year-old female inpatient with moderate COVID-19, confirmed by polymerase chain reaction, and 48% lung damage. Before admission to the hospital, electrocardiogram had no Osborn wave, which first appeared at admission. There was a significant increase in serum C-reactive protein and a moderate increase in serum biomarkers and no changes in intervals and segments on the electrocardiogram. The appearance of Osborn wave may be associated with intramyocardial electrolyte imbalance, a consequence of antiviral and antibacterial therapy that violate intraventricular conduction.