Solvent stable integrally skinned asymmetric nanofiltration membranes were prepared from polyaniline. These membranes were made by phase inversion and then crosslinked using two different chemical crosslinkers, alpha,alpha'-dichloro-p-xylene and glutaraldehyde. The resultant membranes were found to be stable in various organic solvents including acetone, methanol, ethyl acetate, tetrahydrofuran and N,N-dimethyl formamide. Nanofiltration experiments carried out in acetone and dimethyl formamide showed that the membranes gave stable permeate fluxes and good separation performances in the nanofiltration range. Molecular weight cut-off(MWCO) of the membranes was found to be between 150 and 250 g mol(-1). These membranes were also found to be stable for operations at elevated temperatures up to 70 degrees C and possibly higher. Furthermore, no fillers or preservative agents are required to maintain the membranes in a dry state thereby increasing the ease of handling. (C) 2008 Elsevier B.V. All rights reserved.