The sex differences on the WISC-III are reported for the thirteen subtests, the Verbal and Performance IQs, the four Index IQs and the Full Scale IQs in Sudan and the United States. The sex differences are closely similar in the two samples with a correlation of 0.878 (p<0.001) for the thirteen subtests. Males obtained significantly higher Full Scale IQs in the two samples of 0.23d and 0.11d, respectively.