The hair-organ relationship of mercury concentration was investigated in 46 autopsy samples in Tokyo, Japan. Hair mercury levels were highly significantly correlated with organ Hg levels in the cerebrum, cerebellum, heart, spleen, liver, kidney cortex, and kidney medulla, when the total mercury or methyl mercury value in the organ was compared with the hair total mercury or organic mercury, respectively. When the inorganic mercury value was tested, significant correlations remained, with weaker coefficients in all the organs but the spleen. Stepwise multiple regression analysis evidenced that the hair organic mercury value was the major explanatory variable for the organ total mercury or organ methyl mercury value in all the organs. To explain the organ inorganic mercury value, the hair organic mercury value was the major variable for the cerebrum and kidney (both cortex and medulla), the hair inorganic mercury value was the major variable for the cerebellum and heart, and the hair phosphorous and hair organic mercury were the major variables for the liver; no explanatory variable existed for the spleen. Auxiliary explanatory variables accounted for the organ total mercury and inorganic mercury levels, among which the hair selenium value was conspicuous with negative regression coefficients.