Mucormycosis, also known as black fungus, is a rare but aggressive fungal disease with high morbidity and mortality rates that tends to affect patients who are severely immunocompromised. Early recognition of the infection and prompt intervention is critical for treatment success. In recent years the coronavirus disease of 2019 (COVID-19) pandemic has resulted in a surge in the number of cases of mucormycosis. This study aims to report an unfortunate event involving an immunocompromised elderly man with mucormycosis of the foot who died as a result of sepsis caused by COVID-19. It is important to have a high clinical suspicion for mucormycosis when a clinical lesion develops, and to appropriately perform biopsy the lesion in question, particularly in the context of COVID-19. Raising awareness of COVID-19-associated mucormycosis may allow for early detection of the disease, thus enabling the initiation of rapid treatment, ultimately saving lives.