The dimensionality of the Graduate Management Admission Test Verbal and Quantitative measures was assessed using full information factor analysis (FIFA). FIFA, as implemented by TESTFACT, uses marginal maximum likelihood to estimate (reparameterized) discrimination and difficulty parameters of multidimensional item response theory models. The lower asymptote for each item is treated as a known constant whose value is input by the program user. A stepwise FIFA with orthogonal and Promax rotations was run for each measure. In each case a three factor solution was statistically significant. Higher order models were not run, but additional factors might have been significant. For the Verbal measure, the percent variance explained by the three factors in the orthogonal solution was 24.0, 3.7, and 2.6, respectively. For the Quantitative measure, the variance explained by the three factors was 33.7, 3.5, and 1.3. In each case, the first factor is clearly dominant. (19pp.)