Forty-five cases of cervical necrotizing fasciitis are reported, and their clinical, bacteriologic, and therapeutic implications are considered. Fasciitis was of dental origin in 78% of cases, pharyngeal in 16%, and surgical or posttraumatic in 6%. The condition extended to the face in 22% of cases, to the lower part of the neck in 56%, and to the mediastinum in 40%. Soft-tissue cultures were positive in 78% of cases. Anaerobes were isolated along with aerobes in 49% of cases (mean, 2.2 isolates per patient) and in pure culture in 22%. Treatment included surgical debridement and drainage and the administration of antibiotics active against both anaerobic and gram-negative aerobic bacteria. Hyperbaric oxygen was used for adjunctive treatment. The bacteria involved did not affect clinical manifestations, extension, or mortality. The survival rate among our patients was 78%. Mortality was significantly higher among cases with mediastinal extension (44% vs. 7%; P < .01); thus the prompt recognition and drainage of sites of mediastinal extension are of critical importance. Other risk factors for death were an age of > 70 years, underlying diabetes, the development of septic shock within 24 hours after admission, and prolonged prothrombin time.