Fission mass yields for molybdenu~n-99, ruthenium-103 and -105, palladium-109 and -1 12, silver-1 11, cadn~ium-1 15, and tin-121 and -125 In the 25 MeV brenisstrahlung beam fission of thorium-232 and uranium-238 have been determined uslng radiochemical methods. The mass-yield curve for thorium-232 shows a pronounced third peak in the symmetric region, contrary to the results of Hiller and Martin with 69 MeV brebnisstrahlung. In the case of uranium-238, thc curve is flat between mass numbers I I 1 to 121 in contrast to the 14 MeV neutron fission of the nuclide which shows a valley in this region.