AbstractSuspected environmental risk factors for congenital limb anomalies include pesticide exposure to a woman at home or in the workplace. To examine the relationship between congenital limb defect in the infant and pesticide exposure in pregnancy, data on exposure of 155 mothers of limb deficient children born between 1970 and 1981, and 274 matched normal controls, were compared. Case mothers and their matched controls were divided into two groups, those who reported a pesticide exposure in the first trimester of pregnancy and those who did not. The exposure was placed in one of three categories, dependent on proximity of the mother to the source, and the circumstances surrounding use. Statistical analysis indicated a significant association of congenital limb defects with pesticides. A greater risk was associated with exposures to which the woman was in close proximity. When a woman was exposed more than once, there was an increase in risk of limb defect in the child.