The increasing worldwide oil pollution intensifies the needs for new techniques of separation of oil from oily water. Separation by the use of electrospun fibers with selective oil/water absorption is a relatively new but highly promising technique. Owing to their highly specific surface areas, interconnected nanoscale pore structures and the potential to incorporate active chemistry on a nanoscale surface, electrospun fibers have become a promising versatile platform for the separation of oil/water mixtures and emulsions. In this book, after a short introduction to the imperative for oil/water separation and electrospinning technique, it focuses on superhydrophobic/superoleophilic electrospun fibers for oil/water separation, including the preparation of electrospun fibers with superhydrophobic/superoleophilic surfaces and also the superhydrophobic/superoleophilic fibrous membrane for oil absorption and oil filtration. Further, superoleophobic/superhydrophilic electrospun fibers and their application for oil-water separation will be discussed as well.