The mechanisms of production of collective poisoning by pesticides have been contamination of foods consumed by man, cutaneous contact and occupational exposure. It is possible to distinguish 4 groups of alimentary epidemics: (1) contamination during transport or storage; (2) ingestion of seed dressed for sowing: (3) use of pesticides in food preparation because of their organoleptic similarity to alimentary products; (4) presence of pesticides in water or food owing to unsafe use of pesticides. Occupational exposure affects clusters of workers in pesticide manufacture, pesticide application and crop management. Some episodes of every kind of the mentioned groups have been published recently.