Lead concentrations relative to calcium within dated subsamples of hermatypic (reef-building) coral skeletons from St. Croix, US Virgin Islands, record ambient pollution levels. Concentrations within a coral from a polluted reef (395 ng g-1) average five-fold higher than within a coral from a pristine site (87 ng g-1). The lead chronologies of both corals show a significant increase in concentration towards the present during the past 26 yr (1954–1980). The increase in lead concentration in the coral from the pristine site is suggested to represent the increase in lead availability from global pollution. Coral skeletons offer the probability of development into tools for longterm chemical recorders of levels of lead and possibly other metals or compounds in seawater.