The lead diphosphonate and phosphonocarboxylate Pb[HO 3 PCH 2 NHCH 2 PO 3 H] (1) and Pb[O 3 PCH 2 NH 2 CH 2 COO] (2), respectively, have been synthesized under hydrothermal conditions and structurally characterized (crystal data: (1) space group P2 1 2 1 2 1 , a=6.9549(7), b=8.0361(8), c=13.3534(13) Å and Z=4; (2) space group P1, a=4.620(2), b=7.915(3), c=9.895(3) Å, α=104.547(5), β=101.142(5), γ=90.866(5) o and Z=2). In the crystal structure of 1 the Pb 2 + and [HO 3 PCH 2 NHCH 2 PO 3 H] 2 - ions form a three-dimensional framework containing PbO 5 polyhedra. In the crystal structure of 2 Pb 2 + and [O 3 PCH 2 NH 2 CH 2 COO] 2 - ions form a layered structure and PbO 6 units are observed. In both compounds the oxygen atoms of the anions act as bridging as well as monodentate units.