This paper reports on the fabrication of material comprised of chitosan stabilized silver nanoparticles on the carbon paste and its electro-catalytic reduction toward 4-nitroaniline. The synthesized material was obtained when AgNO₃ was mixed with chitosan as a stabilizing agent and NaBH₄ as a reducing agent. The developed Chitosan-AgNPs has been confirmed using UV?Vis spectroscopy, X-Ray diffraction analysis, scanning electron microscopy (SEM) and infrared spectroscopy. The synthesized chitosan-Ag NPs exhibit particle size around 51?nm. To build a voltammetric sensor (Chitosan-Ag NPs/CPE), a carbon paste electrode has immersed in the liquid suspension of chitosan-Ag NPs, thus, it could be employed for electro-catalytic reduction of 4-NA in 0.1?M Britton-Robinson buffer solution (B-R, pH?2). Therefore, the reduction over-potential of 4-NA shifted from ?752.26?mV at CPE to ?304?mV at chitosan-Ag NPs/CPE, and then showing a surface controlled process with the catalytic rate constant (Kcat) of 0.125?×?10^?3 M^?1 s^?1 and a coefficient of diffusion (D) of 2.20?×?10^?6 cm² s^?1 with an enhanced current response. Under optimized conditions, the electro-catalytic reduction peak current of 4-NA increased linearly with increasing of 4-NA concentration over the range of 1?μM to 0.5?mM (R² =?0.9866) with a detection limit of 0.86?μM (3?×?Sb/P).