This report presents a review of literature on organochlorine insecticide of the cyclodiene type endosulfan, which has been employed extensively for agricultural, domestic and public health purposes. It summarizes information on nomenclature and chemistry, metabolism and toxicity in mammals, birds, fishes and insects, degradation and metabolism in plants along with brief reference to the degradation in water and light. Unfortunately, because of lack of knowledge, a precise statement, in regard to the ecological implications and the quantitites of endosulfan now being used, is not possible at this time.