Radiometric dating of the serorogenic Svecokarelian Enkullen and Fjällberg granites, south central Sweden, yield two parallel Rb-Sr whole-rock isochron ages of 1755 ± 17 Ma and 1758 ± 14 Ma, respectively. The initial87Sr/86Sr ratios arc also similar; 0.7063 + 0.0056 and 0.7065 ± 0.0034, respectively. A U-Pb dating of zircons from the Fjällberg granite also gives a corrsponding age, i.e., an upper intercept with concordia of 1748+74-45Ma. A recalculation of the zircons with the U-Pb model of Wickman (1983) yields an age of 1765 Ma. The agreement between the Rb-Sr and U-Pb datings strongly indicates that they represent true primary crystallizing ages.