Diabetes mellitus (DM) and steroid medication, coincided with coronavirus disease 2019 (COVID-19), results in a weakened immune system, allowing some commonly found pathogens to become more harmful. Mucormycosis (black fungus) is a type of opportunistic infection caused by fungi belonging to the Mucorales family. DM is the most prominent risk factor for mucormycosis. Excessive blood sugar and decreased insulin levels lead to diabetic ketoacidosis (DKA), a devastating complication of DM that can be fatal if left untreated. Diabetic ketoacidosis is more common in type 1 diabetic patients, although it can also be fall in type 2 diabetic patients. DKA occurs when the body lacks enough insulin to allow blood sugar to enter the cells and is used for energy. Instead, the liver breaks down fat for fuel-producing chemicals known as ketones. When too many ketones are created too quickly, they can reach dangerously high levels in the body. Mucormycosis is a rare but serious infectious disease that requires medication or surgical removal. The confluence of diabetes and COVID-19 makes managing mucormycosis a serious and dead issue. Although the effectiveness of prophylactic antifungal therapy has yet to be demonstrated, hyperglycemia control appears to be the most important step in managing mucormycosis in DKA patients.