The eleven currently available (May 1980) source mechanisms of Fennoscandian earthquakes are analysed. The orientations of the horizontal stresses involved in the faulting are estimated from the fault solutions. The NW-SE orientation of the largest horizontal compression found in a large number of various investigations in continental Europe north of the Alps, is confirmed by the eleven source mechanisms. This result is shown to be statistically significant. The dominating type of faulting is strike-slip on close to vertical fault planes. The agreement between these earthquakes and the European regional stress field strongly suggests that the Fennoscandian earthquakes are related to tectonic forces.