Silver (Ag) nanoparticles (similar to 3 nm) were synthesized using silver nitrate as the starting precursor, ethylene glycol as solvent and poly (N-vinylpyrrolidone) (PVP) introduced as a capping agent. These nano-Ag particles were reinforced in nylon matrix by electrospinning of nylon-6/Ag solution in 2,2,2-trifluoroethanol and composite nanofibrous membranes were synthesized. The effects of solution concentration and relative humidity (RH) on the resultant fibrous membranes were studied. Scanning electron microscopy and Transmission electron microscopy was used to study the size and morphology of the fibers. It was observed that concentration and RH could be used to modulate the fiber diameter. Tensile test was used to evaluate the mechanical property of these electrospun composite membranes. The composite membranes showed higher strength (approx. 2-3 times increase in strength) compare to as synthesized nylon fibers. (C) 2009 Elsevier B.V. All rights reserved.