Cesium-137 concentration in Japanese beer was determined for the samples of 1959 through 1967. It was found that the level of this nuclide in beer depends on the fallout rate to a great extent and the peak value in beer appears about 1.5 years after the period of the highest rate of 137Cs fallout. The results on certain samples of beer, raw materials (malt, side materials and hops) and the spent residues indicated that almost all 137Cs and K contained in raw materials were transferred to beer during its manufacturing process.