Two granites in western Troms (Ersfjord granite and Rødberg granite), previously thought to be Caledonian intrusives, have been dated by the Rb-Sr whole rock method. A seven-point Rb-Sr isochron age of 1706±15 Ma and an initial87Sr/86Sr ratio of 0.70404±0.00034 (1[sgrave]) was obtained on the Ersfjord granite. An isochron plot of seven samples from the Rødberg granite failed to define an isochron age, but also suggests a Precambrian age for this intrusive. On the basis of these ages it is concluded that no deep-seated reactivation of the Precambrian basement took place in western Troms during the Caledonian orogeny. The ages obtained correlate with the latest episode of mangerite intrusion in the Lofoten-Vesterålen area and with the late syn- and post-kinematic Svecokarelian granites in northern Sweden.