The L(2)(3)NiNa ClO4 complex crystallizes in the monoclinic space group P2(1)/n (No. 14), in a cell having the dimensions a = 17.447(2) Angstrom, b = 13.876(1) Angstrom, c = 19.966(2) Angstrom, beta = 91.16(1)degrees, and Z = 8. The NiN2O2 chromophore adopts a cis configuration resulting in the formation of an outer pseudocavity which can accommodate the Na ion. Unexpectedly, the ClO4 anions not only are integral parts of the structure but also are involved in the organization of the system. Indeed, formation of a dimeric entity is achieved by a bridging ClO4 while hydrogen bonds from the imino groups to terminal and bridging ClO4 link two dimers to yield a "dimer of dimers". [GRAPHICS] GRAPHICS][