Necrotizing fasciitis is a rapidly progressive infection and is a necrosis of the fascia and surrounding tissues. Despite recent advances in its management, outcomes have not improved and mortality rate is still high. Between September 2007 and August 2009, we prospectively studied twenty-four histopathologically proven necrotizing fasciitis patients to assess the prognostic factors that indicate the outcome. Mortality rate was 20.8%. Twelve patients (50%) improved, while seven patients (29.2%) were complicated by limb loss. Mortality rates related to upper and lower limb involvement were similar (20% vs. 22.2%). The rates of gangrene and amputation in patients with diabetes mellitus were significantly higher than other comorbidities. Patients with gram-positive infections had significantly lower rates of amputation (15.4% vs. 54.5%, P = 0.04). Mean band cell count and serum potassium level were significantly higher in the nonsurvivors same as leukocyte count in the patients with gangrene, while serum sodium level was significantly lower in nonsurvivors. We conclude that hyponatremia, hyperkalemia, and increased band cells in the peripheral blood of patients may be useful parameters in distinguishing life-threatening necrotizing fasciitis; hence, we recommended lower threshold to amputation during surgery for this group of patients.