Necrotizing soft tissue infections (NSTIs) are a rare yet highly lethal group of infections presenting as a surgical emergency. Although clinical course is characterized by rapidly progressive tissue necrosis, diagnosis may be delayed due to vague signs and symptoms upon initial presentation. Hence, it is of utmost importance that clinicians are able to make a timely diagnosis in order for the patients to receive appropriate therapy the soonest possible. In this review, we summarize basic epidemiologic and microbiological features of NSTIs, as well as current diagnostic modalities and principles of medical and surgical treatment in this special group of patients.