Individual subtest scores of the Wechsler Adult Intelligence Scale (WAIS) were regressed on measures of the Halstead-Reitan Neuropsychological Battery (HRNB) for 408 psychiatric and neurologic patients. The results suggested that language skills (Aphasia Screening Test), auditory attention (Seashore Rhythm Test), psychomotor speed and general cognitive functioning (Category Test) were underlying the performance in the majority of WAIS subtests. A canonical correlation was performed to consider the degree of commonality between the WAIS and the HRNB. One significant canonical correlation between the linear components of the WAIS and HRNB tests emerged. Canonical variates showed that Block Design, Digit Symbol, and Similarities subtests of the WAIS overlapped with the Aphasia Screening Test and the Category Test of the HRNB. It was concluded that, while shared variance does exist between the WAIS and the HRNB, each offers nonredundant information regarding neuropsychological functioning.