A cross-sectional study of dental caries in the primary teeth as a function of nutritional status was conducted on 1481 children one to 13 years old in Lima, Perú. Forty-one percent of the children were found to be chronically malnourished (stunted), 3% were acutely malnourished (wasted), and 5% were both stunted and wasted. A plot of decayed, extracted, and filled teeth (deft) vs. age resulted in a bell-shaped curve that was shifted to the right by 2.5 years for malnourished groups, compared with normal children (p less than 0.01). The shift to the right of the age distribution of caries was associated with a delay in both the eruption and exfoliation of the primary teeth in malnourished children. Peak caries activity was significantly higher in wasted and in stunted and wasted children, when compared with normal controls. It is concluded that malnutrition delayed tooth development, affected the age distribution of dental caries, and resulted in increased caries experience in the primary teeth.