Feeding during first months of life might affect risk of celiac disease. Individuals with celiac disease or type 1 diabetes have been reported to have high titers of antibodies against cow´s milk proteins. Avoidance of cow’s milk-based formula for infants with genetic susceptibility for type 1 diabetes reduced the cumulative incidence of diabetes-associated autoantibodies. We performed a randomized controlled trial, in the same population, to study whether weaning to an extensively hydrolyzed formula reduced the risk of celiac disease autoimmunity or celiac disease.