Natural radioactive 210Po activities of nine food organisms of tunas were determined. These measurements included individual organ analysis in many instances for making comparisons with recently reported concentrations in the visceral organs of albacore. Of these samples, the highest 210Po activity (61 pCi/g wet) was found on the viscera of a surface-living saury. However, the average concentration in the nine food organisms (2.1 pCi/g wet) was significantly the same as the whole body values (1.5 pCi/g wet) observed in albacore.