The study examined the distribution of CDDP in the inner ear and kidney of guinea pig. Therefore searching for distribution of platinum, sections of inner ear and kidney were not stained with U, Pb and Os were examined with TEM. In the kidney dense electron perticle were found in the cytoplasms of renal tubles. In the inner ear few perticle were found, apert from dense electron substance in cytoplasms of, the outer hair cell. The stronger hearing acuity was impaired, the higher the freqency of, these findings became.