We assessed the effectiveness of food vouchers as a social protection strategy to enhance the adherence to tuberculosis treatment in health-care facilities in Brazil between 2014 and 2017. A cluster-randomized controlled trial was performed in four Brazilian capital cities. A total of 774 adults with newly diagnosed pulmonary tuberculosis were included in this study. Eligible participants initiated standard tuberculosis treatment per National Tuberculosis Program guidelines. Health clinics were assigned randomly to intervention groups (food voucher or standard treatment). The food voucher was provided by researchers, which could be used by subjects only for buying food. Most people with tuberculosis were poor, did receive benefits of the Bolsa Familia Program, and were unemployed. By Poisson regression analysis, with the total number of subjects included in the study, we found that individuals with tuberculosis who received food vouchers had a 1.13 greater risk of cure (95% CI, 1.03-1.21) compared with those who did not receive food vouchers. The provision of food vouchers improved outcomes of tuberculosis treatment and it should be enhanced even further as social protection for people with tuberculosis.