The recently published points of zero charge of metal oxides and related materials are compiled to update the previous compilation (Kosmulski, M., "Chemical properties of materials surfaces." Dekker, New York, 2001). The purity of materials is the most important factor responsible for discrepancies in the literature data. In contrast to the success of new spectroscopic methods in the studies of specific adsorption, the progress in studies of primary surface charging of oxides over recent years is less spectacular.