This review focuses on advances reported from April 2009 to May 2011 in PDMS surface modifications for the application in microfluidic devices. PDMS surface modification techniques presented here include improved plasma and graft polymer coating, dynamic surfactant treatment, hydrosilylation-based surface modification and surface modification with nanomaterials such as carbon nanotubes and metal nanoparticles. Recent efforts to generate topographical and chemical patterns on PDMS are also discussed. The described surface modifications not only increase PDMS wettability, inhibit or reduce non-specific adsorption of hydrophobic species onto the surfaces in the act, but also result in the display of desired functional groups useful for molecular separations, biomolecular detection via immunoassays, cell culture and emulsion formation.