Moldy corn was substituted for normal corn in four dietary treatments to provide 0, 2.1, 3.7 and 4.8 ppm of zearalenone. The diets were fed to gilts from the day after first observed estrus through two gestation-lactation periods. Each diet was fed to 11 gilts initially. Overall reproductive performance appeared to decrease as the level of moldy corn in the diet increased, with fewer sows completing two parities and fewer piglets weaned per litter, especially from sows fed the highest level of moldy corn. Three-week-old gilts that nursed sows fed the highest level of moldy corn had increased weight of reproductive tracts. In 35-d-old gilts, symptoms of estrogenism increased as the level of moldy corn in the diet increased, even though there were no symptoms of estrogenism in the mature gilts or sows fed the same diets. Neither zearalenone nor its metabolites (a- and β-zearalenol) were detected in milk obtained 1 or 14 d postpartum.