Biliary excretion of cadmium was studied in two groups of five rats which were given repeated injections of 109Cd. The first group was given a total amount of 6 mg Cd/kg which was 6 times as much as the second group. The elimination of cadmium in bile, urine, and feces was measured 4 to 5 weeks after the last injection. The relative biliary excretion of cadmium was the same in both groupetion, which was 0.001% but, less than the total fecal elimination of cadmium, which averaged 0.034% during the same time.