This systematic review synthesizes the evidence pertaining to the impact of deworming on parasite load, nutritional status, and other health outcomes of nonpregnant adolescent girls and adult women. Evidence from 4 randomized controlled trials suggests that mass deworming probably reduces the prevalence of soil-transmitted helminth infections, but that it may have little or no effect on anemia and iron deficiency in adolescent girls and nonpregnant women in comparison to no intervention or placebo, and further, that the effect on severe anemia is uncertain. The authors highlight the scarcity of available data and the moderate to very low quality of evidence.