Tungsten CMP involves a synergistic interaction of electrochemical and tribological (wear) phenomena. So far, numerous studies have been conducted using static electrochemical measurements as well as some polishing experiments. In this study, we present some results obtained from carrying out potentiodynamic measurements and tribological experiments in a reciprocating sphere-on-plate tribometer, which allowed a precise control of mechanical and electrochemical conditions. In addition, anodic current-time transient measurements were also used to characterize the kinetics of tungsten passivation reaction. These results indicate that the presence of an passive film is essential for wear of tungsten to take place.