Carbon steel is a candidate material for radioactive waste containers in several countries. This paper summarises and reviews the research that has been carried out within the U.K. and Swedish national programmes to assess the corrosion behaviour of carbon steel in the various environments expected during waste disposal, for cementitious and bentonitic backfill materials. It reviews the relevant environmental conditions and the corrosion processes expected during each stage of waste disposal, then considers the general corrosion and localised corrosion behaviour of carbon steel in both atmospheric and aqueous conditions. Particular emphasis is placed on the long-term anaerobic corrosion processes which will occur under reducing conditions in a waste repository. The review also discusses expansive corrosion, galvanic corrosion and radiolytic corrosion of carbon steel during waste disposal.