Industrial plastics, biomedical polymers and numerous other polymeric systems are contacted with water for everyday functions and after disposal. Probing the interfacial molecular interactions between widely used polymers and water yields valuable information that can be extrapolated to macroscopic polymer/water interfacial behaviors so scientists can better understand polymer bio-compatibility, hygroscopic tendencies and improve upon beneficial polymer behavior in water. There is an ongoing concerted effort to elucidate the molecular level behaviors of polymers in water by using sum frequency generation vibrational spectroscopy (SFG). SFG stands out for its utility in probing buried interfaces in situ and in real time without disrupting interfacial chemistry. Included in this review are SFG water interfacial studies performed on poly(methacrylate) and (acrylate)s, poly(dimethyl siloxane)s, poly(ethylene glycol)s, poly(electrolyte)s and other polymer types. The driving forces behind common water/polymer interfacial molecular features will be discussed as well as unique molecular reorientation phenomena and resulting macroscopic behaviors from microscopic polymer rearrangement. (C) 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2013