1. Numbers of erupted primary teeth were counted in young children in four rural villages in The Gambia. The ages of all children were precisely known, and their heights and weights were measured.2. The majority of children were recorded as having an even number of teeth. The number of primary teeth present in children of given age varied widely. Up to 18 months of age, the Gambian children lagged behind American and European children in number of erupted teeth.3. From the distributions, it appears that a child having no teeth is unlikely to be over 12 months of age, and one with all primary teeth is unlikely to be under 20 months. Between these dental limits, estimates of age from the number of primary teeth present are likely to be accurate to ± 3 or 4 months.4. Children who were tall or heavy for age tended to have more teeth than those who were short or light. Thus, children with delayed dentition would be systematically assessed as younger than true chronological age.5. There was, however, no evidence that slow growth was associated with prolongation of the total period of dental eruption, nor that seasonal variations in rate of growth were associated with similar variations in rate of tooth eruption.