Colleges and universities often permit students classified as learning disabled (LD) and other students not classified as LD to substitute courses for or waive the foreign language requirement. The Modern Language Aptitude Test (MLAT) has become an increasingly popular assessment tool to determine which students can or cannot pass foreign language courses and to diagnose a "disability" for foreign language learning. However, the use of the MLAT for these purposes has both theoretical and psychometric problems. These problems include misusing the MLAT to diagnose a learning disability or to classify students with a disability for foreign language learning; using a single test score to recommend course substitutions and waivers; using outdated test norms; and misunderstanding of the foreign language aptitude concept. The authors conclude by describing appropriate and inappropriate uses of the MLAT. (Contains 9 notes.)