We study the random walk in random environment on Z+ = {0, 1, 2, . . .}, where the environment is subject to a vanishing (random) perturbation. The two particular cases that we consider are: (i) random walk in random environment perturbed from Sinai’s regime; (ii) simple random walk with random perturbation. We give almost sure results on how far the random walker is from the origin, for almost...