A special session on geomembranes in landfills took place on 23 September 2002 at the 7th International Conference on Geosynthetics, held in Nice, France. The session was co-chaired by J.P. Giroud and Nathalie Touze-Foltz. During this session, six papers were presented (see references at the end) followed by a long discussion. Participants in the discussion included panel members (John Bowders, Joe Fluet, Grace Hsuan, Toru Inui, Ian Peggs, Patrick Pierson, André Rollin, Kerry Rowe, and Hartmut Schroeder) and members of the audience. An edited summary of the discussion is presented below. It should be noted that a considerable amount of editing has been done and the participants to the discussion were given the opportunity to review the edited text and enter additional comments. Three topics were addressed during the discussion: (1) advective flow and diffusion through geomembranes; (2) numbers of holes in geomembranes; and (3) types of geomembranes used in landfills.