The returns to years of school completed in family income were estimated for white males and females respectively with data from the 1970 U.S. Census and from eight U.S. national surveys conducted from 1972 to 1980. On the average, the estimated return to a year of school was about 25 percent greater for females than for males. The male-female difference in the increment of family income from the next lower educational level was especially great for persons with one to three years of college, and that increment for females is attributable very largely to marriage rather than to personal achievement. Several implications of the findings are discussed.