Improvements of surfactant flooding in enhanced oil recovery during the last 10 years are discussed. The review starts by giving a short introduction to the principles of traditional surfactant/polymer flooding in sandstone reservoirs. Progress to improve the flooding technique by simplifying the chemical formulation in a viscous displacement of oil is reviewed. Factors related to surfactant-polymer properties, interfacial tension, interaction between chemicals and rock, phase behavior, and possible phase gradients are discussed. The experience of performing chemical floods at three-phase and two-phase conditions without alcohol present is presented. The status of spontaneous imbibition of water and aqueous surfactant solution into lowpermeable chalk material containing oil is brought up to date. Special focus is given to interfacial tension, wettability, and height of the chalk material. The imbibition mechanism is discussed in terms of forces related to capillary pressure, gravity, and possible gradients in surface tension.