Dam decommissioning may involve the complete or partial removal of the concrete or masonry structure: as a big amount of material has to be demolished, its management has to be attentively considered, taking into account also the environmental effects. A valuable alternative to its disposal into waste landfills is the possible recycling in the construction industry, especially as aggregates for concrete. In fact, dam concrete or masonry rubble is a contaminant-free material with steady properties and a fast, easy handling, with little processing, is generally involved. The aim of the present experimental study is to extend the possibility of recycling dam concrete and masonry demolition waste to the production of high quality recycled structural concrete. Aggregates obtained through a crushing process of real concretes and stone masonries from old Italian dams were characterized and used in new recycled concretes, replacing all the coarse natural aggregate and, in different percentages, also the natural sand. The presence of the mortar adherent to the recycled particles was responsible for the low density and the high water absorption values of the recycled aggregates. A suitable pre-saturation procedure has been adopted to maintain the same concrete workability level of the reference concrete, made with natural aggregate. Using a cement content of 400 kg/m3 and a water/cement ratio of 0.5 it was possible to produce new recycled concretes with compressive strengths (30 to 40 MPa) equal or even lightly higher than those of the source dam concretes, also in the case of sand replacement by recycled fine particles, at least up to 10% of total fines. Even if compressive strength and elastic modulus were generally lower (20 to 30%) than those of reference concrete, high quality recycled concretes were obtained, with mechanical performances meeting the Italian and European Standards requirements for structural concrete.