A pump assembly is provided with a pump (6) having one or more pump stages (10), wherein at least one of the components (12, 14) of the pump assembly, whose axial length depends on the number of pump stages (10). On at least one of its axial ends, the component has no connection configuration which is formed in the component (12, 14) itself and which is limited to the axial end. Instead, it is connected at this axial end with a friction fit and/or a positive fit to a connection element (20) which is coupled and/or connected to adjacent parts of the pump assembly, or is provided for coupling to adjacent parts of the pump assembly.