Samples of whole enamel prepared from 83 teeth were analyzed for the concentrations of 30 trace elements. Samples were from lifelong residents, younger than 20 years of age, of a high-caries area (Oregon) and a low-caries area (California). All samples were caries-free, prepared by standardized methods, and analyzed by spark source mass spectrometry by one laboratory. Elements strongly associated with a high prevalence of caries were copper, and, to a lesser extent, aluminum, sulfur, titanium, chromium, nickel, silver, and tin. A low prevalence of caries was associated with high concentrations of strontium in enamel.