Intelligence tests are usually part of the assessment battery for the diagnosis of adults with learning disabilities (LD) and attention deficit hyperactivity disorder (ADHD). Professionals must ensure that inferences drawn from such test scores are equivalent across populations with and without disabilities. Examination of measurement equivalence provides a direct test of the hypothesis that the same set of latent variables underlies a set of test scores in different groups and metric relationships between observed scores and the corresponding latent variables are the same. The hypothesis of measurement equivalence was examined in two samples of college students: one sample with LD and one sample with ADHD. Scores on the third editions of the Wechsler Adult Intelligence and Memory Scales were compared with an age-matched subset of the conorming sample. Results supported the assumption of measurement equivalence but revealed marked differences across samples in latent variable variances and covariances and latent variable means. (Contains 4 tables.)