Necrotizing fasciitis is a rapidly developing, fatal bacterial infection that can ocur in any part of the body. It can occur after trauma, around foreign bodies in surgical wounds, or can be idiopathic. The disease is more common in old patients who have diabetes mellitus, peripheral vascular disease, chronic renal failure, iv drug abuse, alcoholism, or obesity, as well as in immuno-suppressed patients. Necrotizing fasciitis is a polymicrobial infection of the skin, subcutaneous tissue and fascia with a fulminant course and a high morbidity and mortality. We describe a case of necrotizing fasciitis involving the posterior thorax wall, bilateral walls of thorax and right breast. It rarely affects the breast. Mortality due to this condition can be dramatically reduced by early diagnosis, aggressive resuscitation, and ruthless debridement.