A possible connection has been suggested between strontium and a low prevalence of dental caries. An investigation of this subject was initiated by measuring the strontium content of deciduous teeth by atomic absorption spectrophotometry in different regions in Finland. The material analysed consisted of a total of 2,482 tooth crowns and 392 tooth roots. The results showed that the Sr content of the tooth crowns in northern Finland was about two–fold that in the south, about 400 and 200µg/gCa, respectively. The difference was apparently caused by corresponding differences in dietary strontium. The tooth roots contained much more Sr than the crowns, about 600 and 200µg/gCa, respectively, in southern Finland, presumably owing to changes occurring in the dietary habits of the child during the development of the crowns and roots of the deciduous teeth.