New Np(V) complexes with imidazole, [NPO2(CH3COO)(Im)(2)(H2O)], [(NPO2)(2)(C2O4)(Im)(6)]center dot 5Im center dot H2O, and [NpO2(NO2)-(Im)(4)] were synthesized. Their crystal structures were determined using X-ray single-crystal diffractometry. The crystal structures are confirmed by IR and UV-vis spectroscopic data. In all three complexes, neptunium coordinates the imidazole molecule through the nitrogen atom. These complexes are the first example of direct bonding of the imidazole molecule to the actinide atom. These results suggest that coordination of histidine residue in proteins or other imidazole-containing biologically important molecules could occur under usual biological conditions.