The "ETS"® Proficiency Profile (EPP), a college-level assessment, has been widely used to evaluate general education student learning outcomes (SLOs) in college. The purpose of this study was to investigate validity evidence for the EPP by evaluating the relationship with outcomes such as student retention, cumulative grade point average (GPA), and degree attainment, and by investigating differential validity across subgroups and cross-sectional learning gains. Three main conclusions were drawn from this study: (a) Students made significant learning gains from freshman to senior year using EPP scores; (b) freshman scores showed modest relationships with cumulative GPA at various points in college and senior scores showed strong relations with final-year cumulative GPA; and (c) differential validity was found across gender, race, and college major when looking at the relationship between EPP scores and first-year and sophomore GPA. Implications of these results are discussed.