Na 3Pb (II)[B(O 3POH) 4] was synthesized under hydrothermal conditions. The crystal structure determination from single-crystal X-ray diffraction data ( I4 1/ a, Z = 4, a = 6.9182(8) A, c = 27.309 (3) A, V = 1307.0(3) A (3)) revealed the presence of [B(O 3POH) 4] (5-) oligomers and heterocubane-like units Na 3PbO 4 with mixed-occupied metal cation sites.