Ultrafine polypropylene (PP) fibers as oil sorbents were fabricated via a needleless melt-electrospinning device and were characterized by scanning electron microscopy and contact-angle analysis. PP fibers of various diameters and porosities were obtained by the manipulation of the applied electrical field. The effects of the fiber diameter and porosity on the oil-sorption capacity and oil-retention behavior were investigated. The experimental results demonstrate that for fiber diameter on the microscale, the porosity played a paramount role in determining the oil-sorption capacities. The maximum oil-sorption capacity of the resulting PP fibers with regard to motor oil and peanut oil were 129 and 80 g/g, respectively; these values were approximately six to seven times that of commercial PP nonwoven fabricated through the melt-blown method. In addition, even after seven sorption/desorption cycles, the oil-sorption capacity of the chosen sample was still maintained around 80 g/g, and above 97%, oil could be recovered. This indicated excellent reusability and recoverability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40080.