A facile method for the fabrication of electrospun polyurethane (PU) nanofibres impregnated with Ag nanoparticles (NPs) as an efficient and free-standing surface-enhanced Raman scattering (SERS) substrates is reported here. Electrospinning was used to produce polymeric nanofibrous matrix, while a liquid polyol(ethylene glycol) solvent under low temperature was used not only to reduce Ag (+) to Ag (0) , but also was employed as the in situ growth medium for well-dispersed Ag NPs on the surface of fibre nets. Large enhancement in Raman signals of 4-mercaptobenzoic acid analytes could be realized in the present Ag/PU nanofibres due to the presence of SERS 'hotspots' by means of appropriate interparticle gap.