Large numbers of Clostridium perfringens in food are frequently the cause of a mild form of food illness. The organism if widespread in the environment and occurs normally in soil and in the intestinal tract of animals. Sperulation of large numbers of cells in the intestinal tract of animals results in the release of an enterotoxin that produces abdominal cramps and diarrhea. Animals and serological techniques are used to assay for the enterotoxin. Several selective media and confirmatory tests have been developed for quantitative and qualitative recovery of the organism from foods. Proper sanitation and temperature control can limit occurrence and growth in foods.