Nanotechnologists have discovered new filtering media for effective filtrations. The nanofiber based filtering media, made up of fibers of diameter ranging from 100 to 1000 nm, can be conveniently produced by electrospinning technique. This article addresses the current state of art in filtrations by using the nanofibrous filtering media. These filtering media are being surface modified to improve their spectrum and capture efficiency of filtration. The developmental objectives for improving the nanofiber based filtering media are lower energy consumption, longer filter life, high filtration capacity and easier maintenance; which are elaborated from manufacturing point of view. Some practical constraints like pleating of thin, extremely low weight and delicate membranes are also discussed. Nanofibrous filtering media could be used for filtration of blood, water, air, beverages, gases, chemicals, oils, diesel and petrol, etc. (C) 2007 Elsevier B.V. All rights reserved.