Novel eco-friendly chitosan nanocomposite membranes containing gold nanoparticles and carbon nanotubes (CNTs) have been synthesized. The catalytic activity of the nanocomposites was explored using a model reduction reaction of 4-nitrophenol to 4-aminophenol. Kinetic studies demonstrated that the presence of CNTs increased the rate of the reaction, mainly by reducing the induction time. TEM images confirmed the uniform distribution of gold and CNTs in the chitosan matrices. Scanning electron microscopy micrographs revealed that the inclusion of CNTs led to a more compact and less porous network structure which improved the mechanical properties of the films. Catalytically active membranes prepared from the nanocomposites could be reused at least ten times with no loss of mechanical integrity or catalytic effect, opening up the possibility of using this new, environmentally-friendly catalyst support in a continuous flow system.