Four new zinc and cadmium bisphosphonates [{NaZn(Cl2CP2O6H)(H2O)(5)}](n) (1), [{Cd-2(Cl2CP2O6)(H2O)(4)}center dot H2O](n) (2), [{Zn(Cl2CP2O6Pr2i)(H2O)(3)}center dot H2O](n) (3), and [{Cd-2(Cl2CP2O6Pr2i)(2)(MeOH)(2)(H2O)(2)}center dot H2O](2) (4) have been prepared and their crystal structures determined by single-crystal X-ray diffractometry. Two bisphosphonate ligands were used: clodronate, (dichloromethylene)bis(phosphonate) and its symmetrical P,P'-diisopropyl ester derivative. The structure of the Zn complex 1 is three-dimensional, consisting of one-dimensional Zn-clodronate chains connected to the three-dimensional network by Na+ ions. The structure of Cd complex 2 consists of double layers, and a unique bond was found between the Cd2+ cation and a Cl atom of clodronate. Zn complex 3 consists of one-dimensional chains, but the binding of the bisphosphonate ligands is unique: in 3 the bisphosphonate ligand is only bidentate. Compound 4 is a tetramer, and hydrogen bonds hold the tetramers together, forming a layered structure.