The authors report on an experimental test program on different shear connectors to be used in floor elements where prefabricated concrete beams are to be connected on top of Cross-Laminated Timber (CLT) panels. The objective is to evaluate the level of composite action that can be achieved and the increase of strength and stiffness when combining effectively these structural components in a floor element. Shear tests were performed on 12 specimens in total. The shear connector consists of a steel plate as the common part to connect to both the concrete beam and the CLT panel. To the steel plate, studs or a metal mesh were welded and casted in the concrete beam to form a prefabricated unit. The CLT panel was then attached to the steel plate by screws. The main slip occurred between the CLT panel and the steel plate. The test results show a high ultimate load capacity for all types of shear connectors and a ductile type of behaviour for most of them. The test results for the shear connectors were compared with the capacity obtained from analytical models. Also, the strength and stiffness of partially composite floor elements with these shear connectors were analysed. It was found that from a structural point of view these shear connections are suitable to be used to form floor elements with a high level of composite action.