An intrauterine environment may play a role in predisposing a developing fetus to metabolic diseases during adulthood. We investigated the hypothesis that a maternal diet high in omega-6 polyunsaturated fat can modify the programming of an offspring's glucose tolerance, insulin sensitivity, body composition, lipid metabolism, and insulin signaling. High omega-6 polyunsaturated fat diets were fed to female rats 4 weeks before mating and throughout the gestation period. The offspring were maintained on chow diet. At 3 months of age, indirect calorimetry, oral glucose tolerance tests, and dual x-ray absorptiometry measurements were performed. Triglyceride content and beta-hydroxyacyl coenzyme A dehydrogenase activity were determined in the liver and quadriceps muscle. Expression levels of key insulin signaling pathway proteins were measured in the liver and quadriceps muscle of the 3-month-old offspring. Offspring from the fat-fed dams had significantly increased proportions of both total body fat and abdominal fat. All offspring displayed normal insulin sensitivity and glucose tolerance, although the offspring from the fat-fed dams were significantly more hyperinsulinemic 15 minutes after an oral glucose challenge. Whole body fuel oxidation was not altered. The offspring of fat-fed dams had significantly elevated liver triglyceride content. Insulin signaling protein expression levels in the offspring of fat-fed dams were consistent with reduced hepatic insulin sensitivity but increased quadriceps insulin sensitivity. A maternal diet high in omega-6 polyunsaturated fat evokes programming within the metabolic processes of the offspring that may predispose the offspring to the development of metabolic diseases.