There have been few studies of trace elements in cetaceans from Chinese waters despite considerable potential for contamination by this class of pollutant. Between 1993 and 1996, blubber, liver and/or kidney tissues were collected from 11 Indo-Pacific hump-backed dolphins (Sousa chinensis) and 20 finless porpoises (Neophocaena phocaenoides) stranded in Hong Kong. These tissues were analysed for 12 trace elements (As, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sn and Zn). In general, concentrations of trace elements were similar to those of other cetacean populations and were deemed not to be of any toxicological significance. However, concentrations of mercury in the liver tissues of certain individuals were at levels which could constitute a health risk to the animals (up to 906 mg g-1 dry weight). Cadmium, mercury and selenium were observed to bio-accumulate with age, whereas concentrations of copper were highest in neonatal animals.