Porous gold (PAu) was prepared by a paper-based templating method and was used to investigate the effect of a roughness factor on the electrochemical reduction of 4-nitrophenol (4-NP). Bare and palladium-loaded PAu electrodes showed open porous structures and large surface areas, compared to the bulk Au electrode. Moreover, its backbone structure was adjustable with the intrinsic pore size of the filter paper. As compared to PAu and bulk Au electrodes, the Pd/PAu electrode showed high electrocatalytic activity and a rapid reduction rate in a 4-NP reduction test. The results for cyclic voltammetry and kinetic analysis revealed that intraparticle diffusion through a porous structure and an electrocatalytically-active surface area (i.e., a high roughness factor) are important factors contributing to the enhancement of the electrocatalytic performance of 4-NP reduction.