An acid etch procedure was developed which utilized 1.6 N HCl in 70 per cent glycerol, and provided pure samples of surface enamel suitable for trace element analyses. In-vivo biopsies taken from the two maxillary central incisors of 30 children by the acid etch and the conventional abrasive method showed similar concentrations of fluoride. Acid etch biopsies obtained from 35 additional children were analyzed for fluoride by the electrode and for zinc, magnesium, sodium, lead and strontium by flameless atomic absorption. Mean findings (standard deviations) in ppm were: F 2160 (550), Zn 1620 (460), Mg 1650 (890), Na 3740 (740), Pb 1790 (960) and Sr 67 (20). Unexpectedly high values of lead were found in some of the children, suggesting excessive exposure to this element. It is concluded that the biopsy and analytical procedures used are suitable for surveys of many trace elements in surface enamel.