Lithium-manganese dicarboxylates were prepared as a precursor for the synthesis of LiMn2O4 spinel. The structure and thermal decomposition of dicarboxylates were investigated by means of DTA-TG-MAS, XRD, and FTIR measurements. The results indicated that malonate and tartrate form a mixture of lithium-manganese complex salt and manganese salt, but oxalate and succinate have a chain-like structure in which lithium and manganese ions are linked by a dicarboxylic acid ion. For all dicarboxylates, there is no growth of crystalline intermediates during their decomposition process. Beacuse of its low decomposition temperature, 260 degrees C, the malonate was the most suitable precursor for the preparation of LiMn2O4 spinel.