Produced water is the largest wastewater generated in oil and gas industry and its handling has become a significant issue of environmental concern. Due to its massive production, it has caught the attention of the researchers to find the most effective solution. As the front-runner of advanced fiber materials, electrospun nanofiber membrane (NFM) has high potential for oily wastewater treatment since it offers promising properties such as huge surface area, high porosity, tuneable wettability, great permeability and small basis weight. However, fouling issue and low mechanical strength of NFM will mitigate membrane performance over time. Therefore, membrane surface modification methods are applied to reduce fouling and promote crosslinking of nanofibers to improve the mechanical strength of membrane. In this review, it highlights and summarizes the research and development starting from the design concepts and the synthesis of nanofiber membranes and how membrane modification is important for effective oil/water separation. © 2020 Elsevier Ltd.