In this article, we review studies that have used dietary indexes to assess different aspects of diet in relation to health outcomes and sociodemographic factors in childhood populations of developed countries. Eighty-four papers published from 1980 to mid-2010 including 90 unique dietary indexes were reviewed. Seventy-two indexes were developed (or have been adapted) specifically for childhood populations; 38 of these were used to assess diet-disease associations, mostly of diet and obesity. In the majority of these studies, small inverse associations between dietary indexes and obesity indexes were shown. Children who were younger, female, and from high-income families had better dietary quality scores. Forty-nine indexes (of 90) were compared with other aspects of dietary intakes or behaviors, with correlations ranging from very low to modest (∼r = 0.05-0.50). Only 2 validation studies compared an index with nutritional biomarkers, and correlations were quite weak for most plasma nutrients (P < 0.10). Overall, a large number of indexes have been created and used, but the majority of studies are descriptive. Fewer analytic studies on index-health associations have been performed, and most analyses insufficiently adjusted for confounders. Thus, prospective and intervention research in diverse populations is needed to further test these tools. In conclusion, indexes are potentially useful methods for dietary assessment, because they offer valuable information on overall dietary patterns in children. However, understanding the advantages and limitations when applying them in research and public health settings is important, and more research is needed to further develop their utility.