The overall purpose of this study was to describe the developmental and functional status of young Latino children. We analyzed data from the Hispanic Health and Nutrition Examination Survey and estimated the percentages of young Mexican-American and mainland Puerto Rican children with indicators of developmental need for special services, i.e., low birth weight, use of neonatal intensive care, congenital problems, chronic conditions of developmental concern, functional limitations, and physician diagnoses of medical conditions. Estimates suggest that Puerto Rican children had substantially poorer status than Mexican-American children who, in turn, have indicators that are comparable with those reported for the general population. The difference in status between the two Latino groups merits further investigation.J Dev Behav Pediatr 15:27-33, 1994