Abstract We extend our recent theoretical work on the bending relaxation of H 2 O in collisions with H 2 by including the three water modes of vibration coupled with rotation, as well as the rotation of H 2 . Our full quantum close‐coupling method (excluding the H 2 vibration) is combined with a high‐accuracy nine‐dimensional potential energy surface. The collisions of para ‐H 2 O and ortho ‐H 2 O with the two spin modifications of H 2 are considered and compared for several initial states of H 2 O. The convergence of the results as a function of the size of the rotational basis set of the two colliders is discussed. In particular, near‐resonant energy transfer between H 2 O and H 2 is found to control the vibrational relaxation process, with a dominant contribution of transitions with = , and being respectively the H 2 initial and final rotational quantum numbers. Finally, the calculated value of the H 2 O bending relaxation rate coefficient at 295 K is found to be in excellent agreement with its experimental estimate.