Child labor is a prevalent global public health and human rights problem. It puts children at risk for acute and chronic health problems, in many cases prevents completion of formal education, and thwarts the right to freely choose economic opportunities. According to UNICEF, 218million children between the ages of 5 and 17years are classified as child laborers, and of these, 126million are engaged in what the International Labor Organization calls the worst forms of child labor. This article will review the types of child labor, the health effects, human rights principles and international law, and what public health professionals can do to mitigate this problem.