Many schools use mental ability test scores as a basis for grouping students and planning their educational needs. The widespread use of these test scores throughout public and private schools demands that test items be unbiased. One way in which tests could be biased, that has not been thoroughly investigated, is the inadvertent use of analytical skill items favoring one perceptual orientation over another. This study investigated analytical skill items on the Otis-Lennon Mental Ability Test for field independent bias. Using as analysis of variance and discriminant analysis, the results indicated that the Otis-Lennon Mental Ability Test was biased in favor of individuals with a field of independent perceptual orientation.