• Pesticide preparations are being used in the United States in about 80,000 formulations with over 200 basic chemicals. Deaths ascribed to accidental poisonings by pesticides over a nine-year period have ranged from a high of 151 in 1946 to a low of 104 in 1952. In about 50% of the cases death has been ascribed to arsenic compounds, but in from 10 to 20% the poison has remained unidentified. In some states it is still possible to sell pesticides without adequate labeling or other information that could help to protect the user. The history of a fatal case of poisoning from the occupational use of a mercury-containing insecticide illustrates the need of care, especially when pesticides are used in enclosed spaces. A second case illustrates the frequent impossibility of getting the needed information about the identity of the active chemical when a physician is called to treat a patient who is presumably poisoned. The public must be educated in regard to pesticides even if the constant warnings create anxiety in some users.