Accidents constitute a major health problem, and the prevention of accidental poisoning is an important phase of it. There are now, in the United States, 200 centers actively working on the prevention of deaths from this cause. Their functioning is illustrated by three case histories. A total of 3,926 cases of actual or potential poisoning have been reported to the National Clearinghouse for Poison Control Centers and are here analyzed. Ingestion of medicine accounted for 55% of these cases, the most frequently ingested medicine being acetylsalicylic acid. Data on 7,023 deaths due to accidental poisoning have also been analyzed by the U. S. National Office of Vital Statistics; they show that the importance of salicylate as a poison declines in the older age groups and that in the national experience barbiturates caused 50% of all accidental deaths from drugs. Research has led to the development of new drugs and new methods of treatment. Poison control centers supply up-to-date information on treatment and toxicity to physicians and are in a position to encourage education and research as part of the program of prevention. The private physician must play an important role not only in the treatment of accidental poisoning but also in its prevention.