Necrotizing fasciitis is a rare and often fatal soft-tissue infection involving the superficial fascial layers of the extremities, abdomen, or perineum. Necrotizing fasciitis typically begins with trauma; however, the inciting event may be as seemingly innocuous as a simple contusion, minor burn, or insect bite. Differentiating necrotizing infections from common soft-tissue infections, such as cellulitis and impetigo, is both challenging and critically important. A high degree of suspicion may be the most important aid in early diagnosis. Prompt diagnosis is imperative because necrotizing infections typically spread rapidly and can result in multiple-organ failure, adult respiratory distress syndrome, and death. Although group A Streptococcus is the most common bacterial isolate, a polymicrobial infection with a variety of Gram-positive, Gram-negative, aerobic, and anaerobic bacteria is more common. Orthopaedic surgeons are often the first physicians to evaluate patients with such infections and therefore need to be familiar with this potentially devastating disease and its management. Prompt diagnosis, immediate administration of broad-spectrum antibiotic coverage, and emergent aggressive surgical debridement of all compromised tissues are critical to reduce the morbidity and mortality of these rapidly progressing infections.