The present study shows an eco-friendly and cost-effective method for the simultaneous synthesis and coating of palladium nanoparticles on cotton fabric. The biodegradable leaf extract of Citrus limon was used as a reducing and capping agent in the fabrication using the Dip-coating method. The resulting fabric showed excellent colorfastness. The characterization studies using SEM-EDX confirmed the presence and purity of the palladium nanoparticles on the fabric. The repellency and nanotoxicity of the coated fabric were evaluated using WHO’s cone bioassay and fabric dip test, respectively, against adults and larvae Anopheles stephensi mosquito. The results of both tests showed no visible repellency or toxicity. These findings suggest the potential use of an eco-friendly leaf extract to develop a metal-dyed fabric, with a wide range of applications that can be explored further in UV-shielding, bactericidal, and catalysis.