To research this phenomenon, we searched Medline, Psych Info and the ISI Web of Knowledge for papers published between 1980 and October 2006 documenting health effects of child agricultural work in developing countries. The bibliographies of selected papers were then hand-searched. Since we could identify very little peer-reviewed literature, we included epidemiological studies documenting potentially harmful exposures and broadened our search to include non-peer-reviewed studies published by United Nations agencies. Literature documenting the health impacts of child work in agriculture is scarce, and even fewer studies document these impacts in the developing world. Many of the studies we identified either use secondary datasets or are methodologically weak: they rely on small sample sizes, lack comparison groups or do not attempt to control for confounders