This study examined the joint factor structure of the Wechsler Adult Intelligence Scale-Revised (D. Wechsler, 1981) and Wechsler Memory Scale-Revised (D. Wechsler, 1987) in a sample of 399 healthy young adults (206 women and 193 men) recruited for a normative study in Sydney, Australia: the Macquarie University Neuropsychological Normative Study. Using confirmatory factor analysis, the authors contrasted alternative models of ability in the respective Wechsler scales, focusing in particular on hypotheses relating to memory function. The best-fitting solution comprised a model representing Verbal Comprehension, Perceptual Organization, Attention-Concentration, Verbal Memory and Visual Memory. The results are discussed in terms of the incremental validity of ability assessment, potential for improvement in model-fit, and implications for professional practice.Psychologists often administer and interpret jointly the scores derived from the Wechsler Adult Intelligence and Memory Scales (Flanagan, Genshaft, & Harrison, 1997;Kaufman, 1990). Research with a variety of ability scales suggests that, like other ability batteries, the Wechsler Intelligence Scales sample important dimensions of cognition . As well, evaluation of long-term or anterograde-memory abilities adds to the explanatory power of models of cognition (Atkinson, 1991;Flanagan & McGrew, 1997).Factor analysis of versions of the Wechsler Intelligence scales has been reviewed often (e.g., Kaufman, 1990;Matarazzo, 1972), most recently in the WAIS-IIIAVMS-III manual (Psychological Corporation, 1997). Many studies suggest that a three-factor oblique solution comprising Verbal Comprehension, Perceptual Organization, and Freedom-From-Distractibility provides the best representation of the abilities measured by the 11 subtest scores. Most recently, with the addition of some new subtests, a fourfactor solution for the WAIS-III has been reported (Psychological Corporation, 1997), adding Processing Speed as a factor to the familiar three factors.