Internal partitions, as many nonstructural components, should be subjected to a careful and rational seismic design, as is done for structural elements. A quasi-static test campaign aimed at the evaluation of the out-of-plane seismic performance of Siniat plasterboard internal partitions with steel studs was conducted according to FEMA 461 testing protocol. Four tall, i.e. 5 m high, specimens were selected from the range of internal partitions developed in Europe by Siniat, a leading supplier of plasterboard components in Europe. Under the specified testing protocol, a significant nonlinear pinched behaviour of the tested specimen was observed. The pinched behaviour was caused by the damage in the screwed connections, whose cyclic behaviour was strongly degrading. Both stiffness and strength of the specimens are significantly influenced by the board typology and the amount of screwed connections. Finally, it was concluded that Eurocodes significantly underestimate the resisting bending moment of the tested specimens.