In more than 270 dams worldwide, geomembranes are the main waterproofing component. The geomembrane is generally associated with other geosynthetics performing various functions, thereby forming a geosynthetic barrier. In this paper, uses of geosynthetic barriers in the various types of dams are re- viewed. The types of dams reviewed include: embankment dams (earthfill and rockfill dams), concrete and masonry dams, and roller compacted concrete (RCC) dams. Design and construction aspects are considered, as well as selection of geosynthetic materials and performance (including seepage control and durability). The paper is illustrated using a number of examples of new dams and rehabilitation of existing dams, including examples of the early dams constructed or rehabilitated using geosynthetic barriers in the 1950s, 1960s and1970s.