The hydrophilicity of polytetrafluoroethylene (PTFE) micropowders was easily achieved by modifying the surface with thin polydopamine(Pdop) layer deposited through spontaneous oxidative polymerization of dopamine. Compared with the pure PTFE, the Pdop modified PTFE(PTFE@Pdop) possesses excellent hydrophilic property such as low active ratio, and good dispersivity in water. The quantity of coating and the surface amphiphilic properties were readily controlled by adjusting the deposition time. The tribological properties of the as-prepared PTFE@Pdop micropowders as additives in water were evaluated. The results confirmed that the PTFE@Pdop exhibited good antiwear and friction reduction properties even under low concentration in water. The simplicity of the method makes large-scale production of hydrophilic PTFE possible and may be extended as a powerful route for modification of other organic solid lubricating materials that can be exploited as water-based lubricant additives. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 3145-3151, 2011