Landfills have as their basic task the implementation of a controlled and permanent way of disposing of landfilled waste in order to ensure the protection of the environment from harmful effects. The fundamental issue concerning waste disposal is focused on the efficient isolation of landfill bodies from groundwater as well as from surface water. In order to prevent uncontrolled leakage of leachate into the environment, as well as the collection of surface water that has not been in contact with waste, sealing layers are used. These are specifically systems, which are parts of the landfill, and it is possible to classify them on the base sealing layer and on the cover sealing layer. As for the base sealing layer, this forms a barrier that is placed between the landfill and the natural soil in the substrate. As for the cover sealing layer, it covers the waste and prevents the penetration of rainwater into the body of the landfill. The basic role of the geomembrane in the cover sealing system is resistance to various mechanical influences of the vegetation of the final, ie cover layer. The basic goal of this paper is to show the importance of sealing layers in landfills and the role of geomembrane in the entire system.