Abstract <p>Our structural-geomorphologic and morphometric studies have shown that seismically active areas of Sakhalin Island are distinguished by positive anomalies of nine morphometric parameters of the relief where their values exceed the median. These parameters include the difference between the hypsometric surface and the third order base surface; differences between the first and the second order and between the second and the third order base surfaces; the depth of vertical dissection; the standard deviation of slope aspect; density of weak zones; the height asymmetry, the standard deviation of the Gaussian curvature of the relief taken by the module, and the standard deviation of heights. It is shown that seismically active areas may also be delineated by the values of the seven mentioned parameters (excluding the last two), exceeding the third quartile. The density of weak zones is the most informative: 45% of all earthquake epicenters and 71% of earthquake epicenters with the magnitude of surface waves of ≥5.5 are allocated to small areas (25% of the island area), where the density of weak zones is ≥36 km^–1. Thus, the example of a well-studied seismotectonic territory shows the possibilities of identifying seismically active areas based on a set of geomorphologic characteristics. This result may be in demand when assessing the seismic hazard of areas with mid-mountain relief, where detailed seismological studies have not previously been performed.</p>