Standardized achievement scores and academic locus of control were investigated in 28 father-absent (FA) and 28 father-present (FP) third-grade children of similar IQ characteristics. Father-absent children performed significantly worse than FP children in reading achievement. There were no differences between the two groups for spelling and arithmetic, but FA males performed significantly worse than FA females, whose achievement level was closer to that of the FP males and females. For academic locus of control, FA children, compared with FP children, tended to perceive successful achievement outcomes as being related to external sources of control such as task ease or teacher assistance. On the other hand, the two groups took similar responsibility for their failures. Together, the results of this study suggest that for FA and FP groups of similar IQ characteristics, there is already some evidence of the detrimental effects of father absence on cognitive development by the third grade. Further, the academic locus of control characteristics of the one-parent children suggest that their achievement deficits may become more marked in later grades.