Background COVID-19 due to SARS-CoV-2 was first described in the city of Wuhan in China and spread around the world turning into a pandemic. COVID-19 can affect different organ systems, including the oral mucosa. Aims Although cutaneous involvement has been defined in association with COVID-19, the number of case reports about mucosal involvement by SARS-CoV-2 is limited. Hereby, we report a case of hemorrhagic necrosis on the lip in a patient with paroxysmal nocturnal hemoglobinuria (PNH) and COVID-19 infection and briefly discuss its possible mechanism. Patients The clinical features and causes of hemorrhagic necrosis on the lip in a woman are presented. Results In our patient, we think that PNH-associated dermal micro-occlusions caused extensive painful necrosis of the lip. Additionally, COVID-19-induced endothelial damage helped to develop exaggerated hemorrhagic necrosis. Conclusion This current case presentation will contribute to the literature as another case with COVID-19 triggering mucosal involvement.