The gonadal effects produced by injection of cadmium in the rats are well known. The effects of direct injection into the prostate are less well understood. The present experiments indicated the retention of cadmium by the various lobes of the rat prostate following direct injection of radioactive cadmium into the organ. The cells of the prostate are capable of retaining cadmium in measurable amounts up to at least 6 weeks following the injection. The subcellular fractions were measured with respect to cadmium activity and these are indicated. In addition measurements were made in organs which are known to be affected by cadmium, that is, kidney and the testicle. The affinity of the kidney for cadmium is confirmed. The areas of the prostate gland with a high zinc content appear to retain less cadmium than areas of the gland which are known to have a low zinc content. This suggests a possible zinc protective mechanism.