Nowadays, economic and environmental friendly approaches such as adsorbing to refine wastewater have found great attention. In this regard, nylon-polyaniline nanocomposite web with high dye adsorption capacity is developed. This is implemented through in-situ polymerization of polyaniline on the surface of electrospun nylon-6 nanofibers. The produced nylon-6-polyaniline nanocomposite web successfully adsorbed up to 370 mg/g methyl orange as an anionic dye. Further experiment showed that the web has good potential for reusability due to re-chargeability of the web after desorption of adsorbed dye. SEM, N-2 adsorption/desorption and electrical conductivity results demonstrated that nylon nano fibers provide a substrate with high specific surface area and high affinity to polyaniline chains, both of which allow small connected polyaniline particles to be deposited on the surface of nylon nanofibers. Furthermore, it was found that dopant pH is a crucial factor to enhance the dye adsorption efficiency. In this respect, the highest efficiency is achieved with adsorbents doped at pH = 1. Overall, one can witness that in-situ polymerization on a substrate composed of nanofibers is a clean and economic technique to achieve interfaces with highly efficient dye adsorption. To our knowledge, this is the first time in which this technique has gained attention. (C) 2016 Elsevier Ltd. All rights reserved.