Background: A surge in COVID-19-associated mucormycosis cases has been observed during the second wave of COVID-19 in summer of 2021. Most cases were reported from India. The Delta variant (B.1.617.2) was the most common variant circulating at that time. Mucormycosis is an opportunistic angioinvasive fungal infection with high morbidity and mortality. Methods: We present 10 cases of COVID-19-associated rhino-orbital and rhino-orbital-cerebral mucormycosis managed in a secondary hospital in Oman. Results: The median time for developing mucormycosis was two weeks after COVID-19 diagnosis. All patients were newly diagnosed or already known to have poorly controlled diabetes mellitus. Five patients received corticosteroid therapy for COVID-19. Three patients had severe COVID-19 and died of severe acute respiratory distress syndrome and septic shock. Another three patients died of advanced mucormycosis and cerebral involvement. Despite aggressive medical and surgical intervention, the mortality rate was 60% (6/10). Conclusion: Mucormycosis is an aggressive opportunistic infection with high morbidity and mortality that requires prompt recognition and urgent intervention. Uncontrolled blood sugar, the use of corticosteroids, and immune dysfunction due to COVID-19 are all important risk factors for development of mucormycosis. Worse outcomes are associated with poor glycemic control despite aggressive medical and surgical interventions.