In the title complex, [Zn(C₅H₉NO₇P₂)₂(H₂O)]·2H₂O, the zinc atom is coordinated by two zoledronate anions [zoledronate = (2-(1-imidazole)-1-hydroxy-1,1′-ethylidenediphophonate)] and one water molecule. The coordination number is 5. There is one half-molecule in the asymmetric unit, the zinc atom being located on a twofold rotation axis passing through the metal centre and the coordinating water O atom. The anion exists as a zwitterion with an overall charge of -1; the protonated nitrogen in the ring has a positive charge and the two phosphonates groups each have a single negative charge. Intermolecular O–H⋯O hydrogen bonds link the molecules. An N–H⋯O interaction is also present.