This review was prompted by continued public and professional interest of necrotizing fasciitis as well as worldwide increases in the incidence of streptococcal invasive infections. Our objective was to outline the clinical course of necrotizing fasciitis and delineate factors relating to mortality among 163 diagnosed patients. Over 14 years patients diagnosed with necrotizing fasciitis were reviewed for patient history, comorbid conditions, and progression of clinical course. A logistic regression model was used to identify factors increasing mortality risk among necrotizing fasciitis patients. Nearly 17 per cent of the patients showed no identifiable antecedent trauma. Seventy-one per cent of tissue culture-positive patients (145) had multibacterial infections. Although no streptococcal species were recovered from one-third of these culture-positive patients there was an increase in mortality noted with beta-Streptococcus infections. Ninety-six per cent of the patient deaths were correlated with variables organized into the following categories: 1) patient history (intravenous drug use and age <1 or >60 years), 2) comorbid conditions (cancer, renal disease, and congestive heart failure), 3) characteristics of clinical course (trunk involvement, positive blood cultures, peripheral vascular disease, and positive cultures for beta-streptococcus or anaerobic bacteria), and 4) quantitative timeline of clinical course (time: injury to diagnosis, diagnosis to treatment). Mortality is correlated to patient history, comorbid conditions, and progression of clinical course. Necrotizing fasciitis can occur idiopathically and is generally a polymicrobial infection that sometimes occurs in the absence of streptococci. Clearly the mortality and morbidity associated with necrotizing fasciitis can be decreased with clinical awareness, early diagnosis, adequate surgical debridement, and intensive supportive care.