Hamaker constants of systems involving liquid water are evaluated, within the full Lifshitz theory, by means of a recently proposed model of the dielectric function of this substance [Dingfelder et at, Radiat, Phys, Chem, 53, 1 (1998)], which has been extended in the present work by including terms corresponding to infrared excitations and microwave relaxation, An important feature of the complete model is that, besides a good fit to experimental data, it satisfies the physical constraint provided by the f sum rule. For symmetrical systems interacting across water, calculated Hamaker constants are generally in good agreement with results obtained using the Ninham-Parsegian representation with the Roth and Lenhoff parameters for water.