Mucormycosis is a fulminant fungal infection that occurs most often in diabetic and immunocompromised individuals. Our patient, with uncontrolled diabetes mellitus and multiple systemic disorders, developed postextraction mucormycosis of mandible, an extremely rare complication. An initial clinical and radiographic diagnosis of mandibular osteomyelitis was made and the lesion was treated medically and surgically with curettage and saucerisation. The specimen was sent for histopathological evaluation, which showed necrotic area containing broad aseptate fungal hyphae with right angle branching consistent with mucormycosis. The patient succumbed to multipleorgan failure secondary to septicemia. The disease is usually fatal with a poor survival rate; there is still paucity of literature on the definitive management of this disease involving the mandible. This paper emphasizes the need for correction of underlying immunodeficiency and early diagnosis with aggressive multimodality treatment approach to offer the best chance of survival.