In summary, NPs help in reducing the IFT either alone or in combination with surfactants. Moreover, NPs can also reduce the adsorption of surfactants on reservoir rock surface. However, additional experimental work is required to understand the underlying mechanism of improvement in interfacial properties using NPs. Mainly, experimental studies that have been carried out in this field dealt with determining the optimum NPs concentrations corresponding to minimum IFT. However, there is a lack of information on surfactant-NPs interactions. In addition, there is limited data on the interfacial behavior of surfactants with NPs other than silica. There is a huge potential for further investigation in this area, for example, how interfacial properties are altered if oil is changed from light to heavy or surfactants are changed from cationic to nonionic, zwitterionic or anionic, and so on.