Noma predominantly affects malnourished young children. The pathogenesis of noma is complex and multifactorial, involving interaction between local polybacterial infection on the one hand, and malnutrition, immunosuppression, or systemic bacterial or viral infections on the other hand. Noma is considered to be an opportunistic disease, but the immediate cause is uncertain. Immunosuppression associated with a high HIV load may be an important risk factor in South Africa. Cervicofacial necrotizing fasciitis, on the other hand, occurs mainly in adults. It is frequently a consequence of an odontogenic infection and is characterized by an irregular pattern of rapidly spreading necrosis of fascia, muscle, and skin. We present an unusual case of noma in a 32-year-old malnourished HIV-seropositive female with AIDS in whom, within a period of 3 days, the initial intraoral necrotizing process spread rapidly and caused circular full thickness perforating destruction of the lower lip. Prompt diagnosis and treatment brought about control of the active disease and limited the extension of the established noma and of progression of the disease at other affected oral sites.