The reaction of a square-planar S-donating metalloligand [Pd(aet)(2)] (aet = 2-aminoethanethiolate) with [Pd(NO3)(2)(bpy)] (bpy = 2,2'-bipyridine) gave a new type of S-bridged tetranuclear complex [Pd-4(aet)(4)(bpy)(2)](4+) (1), in which two {Pd(bpy)} moieties are aligned so as to overlap each other by bridging with two [Pd(aet)(2)] units.