Spectrophotometric analyses have been made of common cobalt in the human tissues and organs from autopsies to determine the normal concentration and to estimate the total body amount. Bone has the highest concentration of cobalt among the examined tissues, 0.036 μg per gram of fresh tissue on average. The amount in the total body has been estimated as 1.6 × 10−6% by weight and 0.0011 gram for the standard man of 70 kg body weight. These values are smaller by a factor of 3 than the maximum values presented in the ICRPRecommendations.