A sample of 1,123 sixth, ninth, and twelfth graders in two Southern counties was questioned to ascertain how many children they think is ideal. More than three-fourths of the students in each grade had given thought to an ideal number of children for themselves; fewer had thought about the ideal number for the average American couple. Two and three children were the modal responses; mean ideal sizes were 3.02 for self and 3.16 for the average couple. The range of acceptable fertility behavior, “too few” or “too many” children, is defined by medians of 1.56 and 5.96. Ideal and acceptable family sizes increase slightly in the higher grades. A sex difference in ideals appeared only at grade 12; girls wanted more children. Negroes wanted fewer children than did whites at grade 6, more at grade 12. Size of family of orientation was directly related to ideals at grades 6 and 9, but the relation was curvilinear at grade 12. The direct relation between ideals and socioeconomic status became more pronounced at grade 12. Ideal sizes were larger for Catholics than for other religious groups. The study lends at least minimal support to the notion that early socialization affects ideas about family size.