Superhydrophobic polycaprolactone (PCL) membranes with hierarchical structure were fabricated via alternate electrospinning/electrospraying techniques. Electrospun PCL/methyl silicone oil (PCL/MSO) nanofibers were employed as substrate. PCL/MSO-PCL microspheres (PCL/MSO-PCLMS) hierarchical membrane was prepared via electrosprayed PCLMS as an additional layer on the substrate. Field emission scanning electron microscopy images showed the formation of hierarchical PCL/MSO-PCLMS membranes. Compared to pure PCL fibers substrate (120 +/- 1.3 degrees), the water contact angle (WCA) of MSO-modified PCL membrane was 142 +/- 0.7 degrees. The most interesting observation was that the WCA of PCLMS without any modification could be achieved to 146 +/- 2.8 degrees. On this basis, PCL/MSO-PCLMS hierarchical membrane possessed superhydrophobic surface with 150 +/- 0.6 degrees of WCA. The excellent surface roughness and air-pocket capacity of hierarchical membranes would make the membranes more hydrophobic. The maximum oil (n-hexane) adsorption capacity of PCL/MSO-PCLMS membrane was 32.53 g g(-1). Oil-water separation efficiencies of the superhydrophobic membranes were all higher than 99.93% after 10 cycles. The hierarchically structured PCL superhydrophobic membranes indicate the potential applications of environmentally friendly biopolymers as separation membranes. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 421-430