This study addresses the complex geology caused mainly by tectonic and glaciotectonic processes in lignite-bearing areas of Poland. Tectonics played a dominant role in the deformation of peat/lignite seams during their deposition. This is especially true for deep grabens where the thickest lignite seams were deposited (e.g., Bełchatów). Conversely, glaciotectonics led to the post-depositional deformation of other deposits (e.g., Sieniawa). The effects of tectonic and glaciotectonic processes in this region are investigated using both simplified geological cross-sections and photography. The size, depth and architecture of the glaciotectonic structures verified in this study demonstrate the importance of their consideration during the exploration and exploitation stages of such lignite deposits, as well as the planning of construction projects in areas strongly transformed by glaciotectonics.