This paper presents evidence about the impact on school enrollment of a program in Ecuador that gives cash transfers to the 40 percent poorest families. The evaluation design allows the investigation of whether project impact varies with families’ poverty level. Among the poorest families in the study, the impact is positive while it is equal to zero for less poor households. This suggests that for the poorest families the program lifts a credit constraint, while this is not the case for families close to the eligibility threshold.