Three linear tectonic dislocation groups of different orientation (and probably also of different age) cut the Estonian oil shale-kukersite deposits. Two younger groups of structures are typical fault zones with N-NE and NW trends, which are expressed topographically as narrow valleys, partly infilled by till, both oil land and offshore. The oldest, third group of structures is represented by narrow, somewhat curvilinear, NE-trending folded and fractured zones, associated with extensive dolomitization, hydrothermal mineralization and karst. Oil shale within these structural zones is oxidized, and partly replaced by karst clay. All dislocations disrupt and complicate the structure of deposit, which affects mining conditions from the technical point of view and also causes a loss of oil shale resources.