A key component of current school reform efforts focuses on increasing parental choice through voucher systems and programs that provide tax benefits for contributions to scholarship programs for private school tuition. Indeed, proposals to adopt such programs have been or currently are being considered in four-fifths of the states, and about half of the states have already adopted some type of voucher and/or tax benefit program to assist parents in selecting private education for their children. This article provides an overview of the challenges to school voucher and tax benefit programs under the Establishment Clause of the First Amendment of the U.S. Constitution and/or the religion clauses of state constitutions. Specific sections address pertinent Supreme Court decisions, state constitutional religion clauses, state court cases rejecting religious challenges to voucher and tax benefit/scholarship programs, and cases in which such initiatives have been invalidated under the religion clauses of state constitutions. The concluding section focuses on the viability of future religion clause challenges to such programs and implications of legal developments pertaining to the privatization of schooling in our nation.