The Government of Costa Rica collaborated with a research team to conduct a randomized controlled trial of their Working Children and Adolescents program. The program provided working youth with a monthly cash transfer with the conditions that they attend school regularly and complete their grade. This study examines the effect of the cash transfer on (1) child labor and hazardous child labor participation as well as hours worked; (2) school enrollment, attendance, and completion; and (3) self-reported health. The main findings provide evidence of a statistically significant reduction of more than 4 hours worked per week by children. The findings also suggest null effects on labor participation and school outcomes. Cost-effectiveness analysis shows that the program demonstrates a transfer effectiveness and cost-effectiveness comparable to similar interventions in Latin American countries. The subsidy alone does not seem enough to improve schooling outcomes, justifying the necessity of additional education policies to complement the cash transfer program.