Two low-temperature phases, (II) and (III), of BaCa2(C3H5O2)6 are presented. The first-order phase transition from room-temperature phase (I) to low-temperature phase (II) is accompanied by a rearrangement of the carboxylate groups around Ba2+, with concomitant ordering of some ethyl chains, while phase transition (II)→(III) during cooling has second-order character because it is related just to the ordering of the ethyl chains.