Maximum likelihood confirmatory factor analysis was performed on the WAIS-III data of a sample of 166 patients with traumatic brain injury (TBI). Four competing hypothetical models were tested for model fit and parsimony. A four-factor model composed of Verbal Comprehension, Perceptual Organization, Working Memory, and Processing Speed, identical to that proposed for the standardization sample, provided the best fit to the clinical data. The results support the construct validity of these four factors in patients with TBI.