The number of deciduous teeth in a sample of rural Ladino Guatemalan children was counted every 3 months through 24 months of age, and at 6-month intervals from 24 to 36 months. Nutritional status at birth, whether expressed as full-term birth weight or as maternal caloric supplementation during pregnancy, influences the timing of deciduous tooth eruption. Furthermore, the timing of deciduous tooth eruption seems more closely associated with postnatal weight than with birth weight. Although indices of nutritional deficiencies are associated with retarded tooth eruption, the use of mean number of deciduous teeth erupted as an estimate of mean chronological age in populations living under conditions of mild-to-moderate malnutrition is relatively accurate because errors of age estimation based on mean values for the present sample only vary between 1 and 2 months.