Microfibrous PIM-1 membranes have been produced by electrospinning process. Conditions for the fabrication (concentration of polymer, voltage, feed flow rate and distance between tip and collector) have been investigated, and smooth fibrous materials with an average diameter of 2 tm have been obtained in these following conditions: [PIM-1]=5%wt, voltage=20 kV, flow rate=5 ml/h and distance=16 cm. These membranes presented a high hydrophobic character but a low liquid entry pressure LEP. (C) 2016 Elsevier B.V. All rights reserved.