Abstract In this paper a comparison between historical earthquakes and recent seismic activity in northern Iran is presented. It is shown that for certain parts of the world which have a long well-documented history the problem of earthquake frequency can be solved approximately on the basis of seismic history and local tectonics. Considering the state of development of instrumental seismology and of its interpretation, it is not only inadequate to attempt the assessment of seismicity without due consideration to the earthquake history but it may also be misleading.