Rhinocerebral phycomycosis is a short-term and often rapidly lethal fungal disease in the nose and paranasal sinuses. The phycomycetes, which are ordinarily saprophytic organisms, only under appropriate conditions become pathogenic. This is seen most often associated with diabetic ketoacidosis. By primarily arterial growth they cause inflammation and necrosis to spread from the nose and paranasal sinuses to involve the orbit, cribriform plate, meninges, and brain. The most characteristic rhinologic finding is a black, necrotic turbinate resembling a mass of dried, clotted blood. Early clinical recognition of this disease with biopsy to demonstrate the organism is essential before irreversible changes have occurred. Therapy consists of control of systemic disease, heparinization, the use of amphotericin B local drainage and débridement.