[en] The distribution of gold Au 198 after intraperitoneal administration in dogs and rats was determined by scans and tissue radioassays obtained 24 hours after injection. Relative activity and percent of injected radioisotope contained in different organs were calculated. The radioisotope was found to be heavily concentrated in mediastinal lymph nodes and liver, with liver uptake averaging 36.5 percent of the injected isotope 24 hours after injection. The use of therapeutic intracavitary radiocolloids should be reevaluated in light of possible excessive irradiation of the liver. (U.S.)