In previous studies we investigated the metabolism of tin compounds in rats and hamsters following single oral treatments with triphenyltin. The objective of this study was to provide information on the metabolism of triphenyltin in hamsters subchronically treated with dietary triphenyltin for 180 d. Groups were fed diets containing 3 different triphenyltin concentrations: 1.28, 28.82 or 54.77 ppm. The 28.82 and 54.77 ppm groups gained less body weight than the control and 1.28 ppm groups. However, none of the animals showed characteristic symptoms. We detected triphenyltin and its metabolites in the tissues of dosed hamsters. Highest tin concentrations were in livers and kidneys, as diphenyltin and inorganic tin respectively; no significant amounts of triphenyltin were found. Triphenyltin was metabolized relatively rapidly in the hamsters. There was more tin relative to the administered triphenyltin in the livers of the low dietary group compared to the high dietary triphenyltin group. This suggests that low concentrations of triphenyltin are easily absorbed from the gastrointestinal tract. While we previously demonstrated that acutely dosed triphenyltin produced marked hyperglycemia in hamsters, this was not found in the hamsters repeatedly dosed with dietary triphenyltin in the present study.