This invention involves the recovery of high quality polyols from flexible polyurethane (PU) foam wastes using a two-phase glycolysis process by means of a novel catalyst based on naphthenic salts or mixtures of their components preferably selected from the group of alkaline and alkaline earth salts. The process for preparing a recyclate polyol comprises bringing a polyurethane foam in contact with a glycolyzing compound containing at least two hydroxyl groups, and let the foam and the glycolyzing compound react at high temperature in presence of the naphthenic catalyst. By means of the use of a large excess of a glycolysis agent, much larger than the estequiometric quantity, the reaction product splits in two phases, where the upper layer is mainly formed by the recovered polyol from the PU, and the bottom layer is formed by the excess of glycolysis agent. The upper phase can be purified by a liquid-liquid extraction using an aqueous phase and the excess of glycol of the bottom phase can be recycled to the process by vacuum distillation.