Butyltin compounds (BTs), including mono- (MBT), di- (DBT) and tributyltin (TBT), were identified in the pantropical spotted dolphin, Stenella attenuate, from the coasts of Taiwan. In all 13 cases, the muscle tissues were analyzed. But the liver content was only measured in one of the samples. Dolphin muscle contained BTs ranging from 14 to 202 ng/g wet wt, with MBT dominant in the samples. Sex-differential and age-dependent accumulations of BTs in muscle were not found. The concentration of BTs in the liver was 701 ng/g wet wt, and MBT was dominant (77%). In general, butyltin concentrations in dolphins from the coastal waters of Taiwan are within the range of cetaceans reported worldwide. And to our knowledge, this is the first study reporting on the butyltin pollution of marine mammals in Taiwan.