Using flameless atomic absorption spectrophotometry, platinum concentrations in tissue samples were determined to clarify the distribution and accumulation of platinum in the human tissue after administration of cisplatin. Tissue samples were obtained at the time of autopsies or operation from 14 patients who were given cisplatin 0.7-20.1 mg/kg. Platinum concentrations were highest in the liver and testicle, high in the kidney, lung, heart and spleen, and lowest in the brain. In most organs except the brain, the tissue platinum concentrations increased exponentially according to the total dose of cisplatin. Platinum concentrations in metastatic tumors were generally somewhat lower than those in the normal parts of the organs, with the exception of cerebral metastasis. However, some of the metastatic tumors in the lung and brain showed higher concentrations than those in normal parts of the lung and brain, respectively.