This article evaluates the "mismatch" hypothesis, advocated by opponents of affirmative action, which predicts lower graduation rates for minority students who attend selective post-secondary institutions than for those who attend colleges and universities where their academic credentials are better matched to the institutional average. Using two nationally representative longitudinal surveys and a unique survey of students who were enrolled at selective and highly selective institutions, the authors tested the mismatch hypothesis by implementing a robust methodology that jointly considered enrollment in and graduation from selective institutions as interrelated outcomes. The findings do not support the "mismatch" hypothesis for black and Hispanic (as well as white and Asian) students who attended college during the 1980s and early 1990s.