BACKGROUND Necrotizing fasciitis is a potentially fatal infection involving rapidly progressive, widespread necrosis of the superficial fascia. OBJECTIVE The purpose of this collective review is to review modern concepts of the treatment and diagnosis of necrotizing fasciitis. CONCLUSIONS Necrotizing fasciitis is characterized by widespread necrosis of the subcutaneous tissue and the fascia. Although the pathogenesis of necrotizing fasciitis is still open to speculation, the rapid and destructive clinical course of necrotizing fasciitis is thought to be due to multibacterial symbiosis. During the last two decades, scientists have found that the pathogenesis of necrotizing fasciitis is usually polymicrobial, rather than monomicrobial. Although there has been no published well-controlled, clinical trial comparing the efficacies of various diagnostic imaging modalities in the diagnosis of necrotizing infections, magnetic resonance imaging (MRI) is the preferred technique to detect soft tissue infection. MRI provides unsurpassed soft tissue contrast and spatial resolution, has high sensitivity in detecting soft tissue fluid, and has multiplanar capabilities. Percutaneous needle aspiration followed by prompt Gram's staining and culture for a rapid bacteriologic diagnosis in soft tissue infections is recommended. Surgery complemented by antibiotics is the primary treatment of necrotizing fasciitis. CONCLUSIONS Wide, extensive debridement of all tissues that can be easily elevated off the fascia with gentle pressure should be undertaken. Successful use of intravenous immunoglobulin has been reported in the treatment of streptococcal toxic shock syndrome. The use of adjunctive therapies, such as hyperbaric oxygen therapy, for necrotizing fasciitis infection continues to receive much attention.