A Pd-6 molecular cage [{(tmen)Pd}(6)(bpy)(3)(tma)(2)](NO3)(6) [1; where tmen = N,N,N,N-tetramethylethylene diamine, bpy = 4,4'-bipyridyl, and H(3)tma = trimesic acid] was prepared via the template-free three-component seff-assembly of a cis-blocked palladium(II) acceptor in combination with a tricarboxylate and a dipyridyl donor. Complex 1 represents the first example of a 3D palladium(II) cage of defined shape incorporating anionic and neutral linkers. Guest-induced exclusive formation of this cage was also monitored by an NMR study.