Necrotizing fasciitis is a hypodermis, muscular fascia then dermis necrotizing infection. It disseminates along fascias with a mortality sometimes within 18 hours. The average mortality, reported in the literature, is about 30%. A 65-year-old man, with a history of Vaquez disease (under hydroxurea) and a smoke addiction, had an epidermoid carcinoma of the left vocal cord (T2 N0 M0). The cancer treatment consisted of a functional lymph node excision, followed by tracheotomy then by partial laryngectomy. At the end of the intervention, after removal of operative fields, it was noticed that the Montandon cannula had slid and was between the medial side of the left upper limb and the lateral side of the chest. There was a cutaneous imprint with ecchymosis on the route of the cannula. At the second postoperative day, a necrotizing fasciitis quickly developed on the left side of the chest, the medial side of the left upper limb, and the left hip without infection of the operating site. An Escherichia coli was identified in tracheal secretions and operative samples. The presumed hypothesis of this necrotizing infection is the cutaneous contamination of the thoracic wall by tracheal secretions colonized by E. coli, whose penetration was induced by the cutaneous traumatism due to the cannula. We remind, by analyzing this unusual case, the caring principles one of which diagnosis and the surgical excision must be as premature as possible. We insist on the elementary measures of protection of the support points and the good binding of cannulas.