Necrotizing soft tissue infections (NSTIs) are surgical infections known for being difficult to diagnose and having a high mortality. Familiarity with this disease is particularly critical for emergency physicians, as delay in diagnosis or mistakes in treatment are associated with higher mortality, morbidity, and amputation rates. This article will review the pathophysiology and microbiology of NSTIs and describe the current literature on diagnosis of NSTIs. Key concepts in management will be covered, including antibiotic selection, critical care pearls, and surgical management. After reading this review, emergency physicians should feel comfortable with best practices in NSTI care.