A prospective investigation about the influence of the tabagism and its characters on the laryngeal cancer has been led in the department of oncology in the Hospital Center Ibnou Rochd in Casablanca from December 1990 to June 1991. The investigation concerned 58 new patients. We conclude from this investigation that the risk of cancer increases with the intensity of the tabagism (the precocious age at the beginning, long duration, high number of packets/years; black tobacco, deep inhalation of the smoke, absence of weanling). The risk increases with the association with an intense alcoholism. We don't find the professional exposition. These cancers related to tobacco have epidermoid predominance. Finally, the major interest of this study is to convince us about the ampleness of this flail and to lead us through an educative action for the preventive fight against tobacco because of the risk of laryngeal cancer.