This paper examines the short-term behaviour of innovative slim floor steel-timber shear connections through push-out tests. Sixteen specimens were subjected to monotonic loading parallel to the timber grain. The shear connections adopted mechanical fasteners such as coach screws of various diameters or dowel bars, and a combination of the two. In addition, to complete load-deformation curves, yield characteristics, and failure patterns were assessed. For the screwed connection, failure often involved one or two plastic hinges and localised timber crushing near the screw. In the case of dowel bars, the formation of a central plastic hinge in the steel element was also associated with localised timber crushing. Experimental observations indicate that the diameter of the connector has a direct influence on the specimen stiffness and strength and. The combination of screws and dowels provides higher stiffness, strength, and ductility, compared with cases when either screws or dowels are used. The strength of specimens with combined shear connectors was about 61% and 95% higher than that of those with screws and dowels, respectively. Comparative assessments between experimental results and existing design expressions indicate that the codes tend underestimate the strength, yet these are suitable for the design of the slim-floor shear connections.