Despite heightened scrutiny of the use of standardized tests in college admissions, there has been little public empirical analysis of the effects of an optional SAT score submission policy on college admissions. This paper examines the results of the decision by Mount Holyoke College to make SAT scores optional in the admissions process. We find that students who ''under-performed'' on the SAT relative to their high school GPA were more likely to withhold their scores; the admissions office rated applicants who withheld their scores more highly than they otherwise would have been rated; and, matriculants who withheld their scores had a lower average GPA than those who submitted their standardized test results.