The paper addresses the issue of child labor in relation to the educational attainment of working children. The empirical analysis is based on household surveys in Bolivia and Venezuela. It was found that labor force participation is non-trivial among those below the legal working age or supposed to be in school. Working children contribute significantly to total household income. The fact that a child is working reduces his or her educational attainment by about 2 years of schooling relative to the control group of non-working children. Grade repetition, a common phenomenon in Latin America, is closely associated with child labor.