To elucidate the relationship between peroxisome proliferation by perfluorinated compounds and oxidative DNA damage , perfluorooctanoic acid (PFOA) , perfluorodecanoic acid (PFDA) , perfluorobutyric acid (PFBA) and perfluorooctane (PFO) were administered to 6 -week-old F-344 male rats. After a single intraperitoneal (i.p .) injection of PFOA, PFBA or PFO in corn oil at a dose of 100 mg/ kg, significant increases of liver weight and 8-hydroxydeoxyguanosine (8-0H-dG) levels in liver DNA were observed in PFOAtreated rats. Oral administration of powdered diet containing 0.02 % PFOA or 0.01 % PFDA for 2 weeks resulted in significant increases of liver weight and 8-0H-dG levels in liver DNA in rats given both chemicals. On the other hand, no increase in 8 -0H-dG levels in kidney DNA was found in either of the studies. Our results demonstrate that, as with other peroxisome proliferators (phtha/ic ester plasticizers and hypolipidemic drugs) , PFOA and PFDA induced peroxisome proliferation also leads to organ specific oxidative DNA damage .