Fishes commonly consumed in Taiwan were purchased from four fish markets at seasonal intervals in 2006 in order to monitor the butyltin residues, including monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), and tetrabutyltin (TeBT), in fishes caught along the west coast of Taiwan. Concentration of MBT, DBT, TBT, and TeBT in the muscle or the internal organ of these fishes were in the range of n.d.–949.2 ± 49.1, n.d.–56.2 ± 7.9, n.d.–70.8 ± 10.0, and n.d.–103.8 ± 76.9 ng/g (wet weight), respectively. Owing to the toxicological similarity between DBT and TBT, total concentrations of DBT plus TBT in the muscle or the internal organ were taken as the standard for the residue level of butyltins and they were found lower than the tolerable average residue level (TARL) of 175.4 ng/g (wet weight). Therefore, butyltin levels in fish from Taiwanese markets are not a matter of concern for public health.