Washington, DC's Opportunity Scholarship Program (OSP), the only federally funded school voucher program in the United States, has provided private school scholarships to low-income students in DC since 2004. From its inception, the program has received significant attention in national debates and has been the subject of rigorous evaluations mandated by Congress. We conduct an experimental evaluation of the effect of the OSP on college enrollment by comparing the college enrollment rates of students offered a scholarship in lotteries held in 2004 and 2005 with those of students who applied but did not win a scholarship. Students who won scholarships to attend private schools were not significantly more or less likely to enroll in college than students who did not.