To the Editor .—In the November 1967ArchivesI reported having observed patients with carcinoma of the larynx who had been exposed to insecticides which caused severe throat irritation. Dr. Snyder of the Sloan-Kettering Institute for Cancer Research requested further information on these patients. Report of Cases The short case histories follow: Case1.—A 24-year-old white landscaper complained of increasing hoarseness. This patient has never smoked, rarely ingests alcohol, and states that in the four years in his vocation he has developed a severe throat irritation when using pesticides, especially Isotox spray (commercial name). This patient developed an epidermoid carcinoma on the anterior one-third of the left vocal cord and I performed a hemilaryngectomy on Aug 15, 1966. Case2.—A 69-year-old white woman, a horticulturist, has never smoked or ingested alcohol, has spent approximately ten years in the florist business, mainly inside greenhouses with exposure to pesticides, Malathron 50 and