Educational vouchers are the most controversial of numerous school-choice alternatives. This ERIC Digest in Spanish provides some background on the topic and discusses the support educational vouchers has received, as well as arguments for and against vouchers. The digest supplies information concerning the degree of success for voucher programs and cites some studies that found consistent, generally positive results regarding inclusion of low-income families, parent satisfaction, parent education levels, parent marital status and family size, race-ethnicity, and attrition and mobility. Findings were inconclusive or inconsistent regarding student achievement and parental involvement. Two final sections discuss the constitutionality of publicly financed voucher plans and major policy issues and recommendations. Vouchers may be constitutional in some states, but not in others. During the past decade the High Court appears to have become more willing to allow state aid to flow to sectarian schools. Major policy issues include voucher plan effects on private schools, accountability, and program quality. (Contains 13 references.) (DFR)