The aim of this pre-birth cohort study was to examine the associations between maternal intake of vegetables, fruit, and antioxidants during pregnancy and behavioral problems in Japanese children 5 y of age.Participants were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional, conduct, hyperactivity, and peer problems, as well as low prosocial behavior were assessed using the parent version of the Strengths and Difficulties Questionnaire. Adjustment was made for maternal age, gestation at baseline, region of residence, number of children, maternal and paternal education, household income, maternal depressive symptoms during pregnancy, maternal alcohol intake during pregnancy, maternal smoking during pregnancy, child's birth weight, child's sex, breastfeeding duration, and smoking in the household during the child's first year of life.Maternal intake of total vegetables and green and yellow vegetables during pregnancy was independently inversely associated with childhood low prosocial behavior. Maternal intake of other vegetables during pregnancy was independently inversely related to childhood hyperactivity problems and low prosocial behavior. Maternal intake of fruit and apples during pregnancy was independently inversely related to childhood hyperactivity problems. Maternal intake of citrus fruits during pregnancy was independently inversely related to childhood emotional, conduct, and hyperactivity problems. Maternal vitamin C intake during pregnancy was independently inversely associated with childhood conduct and hyperactivity problems and low prosocial behavior.Maternal intake of vegetables, fruit, and vitamin C during pregnancy may be preventive against any of the behavioral problems assessed here except for peer problems in Japanese children 5 y of age.