Acidic urates [Mn(HL)(2)] . H2O, [FeOH(HL)(2)](2) . 4H(2)O, [Co(HL)(2)(H2O)(2)] . 2H(2)O, and [Ni(HL)(2)(H2O)(2)] . 2H(2)O (H2L is uric acid) were synthesized and their structures and physicochemical properties were studied using IR spectroscopy, diffuse reflection spectroscopy, DTA, and magnetochemistry methods. The metals were shown to coordinate the urate anion through oxygen and nitrogen atoms. The [FeOH(HL)(2)](2) . 4H(2)O complex has a dimeric structure.