Over the last twenty-five years, researchers have become greatly interested in the effects of family structure on the academic achievement of children. The vast majority of these studies have focused on one or two family structures in their analysis. There remains, however, a considerable amount of debate about which of these family structures impacts the academic achievement of children the most. Using the NELS data set from the 1988-1992 period, the effects of seven family structure variables were examined to determine the extent to which several family structures impact the academic achievement of children. The results of this study indicate that the effects of family structure on the academic achievement of children vary considerably among the most common family structures. When SES, race, and gender are not controlled, living with a nevermarried single-parent or living with a remarried widow(er) had the greatest impact on the academic achievement of children. When these variables are controlled, living with a cohabiting couple or a remarried widow(er) had the largest impact on the academic achievement of children.