BACKGROUND The worldwide spread of the severe acute respiratory syndrome-coronavirus-2 (SARS-COV-2) has created unprecedented situations for healthcare professionals and healthcare systems. Although infection with this virus is considered the main health problem currently, other diseases are still prevalent. CASE REPORT This report describes a 59-year-old man who presented with symptoms of dyspnea and fever that were attributed to Covid-19 infection. His clinical condition deteriorated and further examinations revealed a subjacent severe aortic regurgitation due to acute infective endocarditis. Surgical treatment was successful. CONCLUSIONS The results of diagnostic tests for Covid-19 should be re-evaluated whenever there are clinical mismatches or doubts, as false-positive Covid-19 test results can occur. Clinical interpretation should not be determined exclusively by the Covid-19 pandemic. This case report highlights the importance of using validated and approved serological and molecular testing to detect infection with SARS-CoV-2, and to repeat tests when there is doubt about presenting symptoms.