Lightweight concrete (LWC) has advantages over conventional concrete (CC). For the same strength value, LWC has a lower weight so the load over the structure is reduced. However, CC produces shorter deflections for the same load. The combined use of both materials could optimize the best behavior of each. The goal of this paper is to study experimentally the multilayer LWC and CC beam behaviour. It is compared against monolithic LWC and CC beams. Keywords: Lightweight concrete, multilayer beam