Polymer flooding is an excellent candidate for enhancing recovery factor through increasing volumetric sweep efficiency. Polymers are generally used to increase the viscosity of the displacing fluid. These chemicals significantly reduce the mobility ratio between the displacing and displaced fluid. This paper aims to provide a comprehensive review about enhanced oil recovery (EOR) methods, pros and cons of polymer flooding, modified conventional polymers, and novel smart polymer. The properties of conventional and novel water-soluble polymers applied in EOR are discussed along with their limitations. In addition, this review covers current research studies about new smart polymers and properties which suitable for high temperature and high salinity reservoirs, overcoming limitations due to harsh reservoir conditions.