In the interests of using green and sustainable chemical innovations to create sustainable products with minimized (or no) chemical hazard potential, the polyester fabric in this work was activated and functionalized with chitosan and its durability was investigated. Chitosan is a natural biopolymer derived from chitin. As it has good biocompatibility, bio-absorption, anti-infectious, antibacterial and hemostatic properties and accelerates wound healing, it is increasingly being researched for the antimicrobial treatment of textiles. Due to the increased demands on the durability of antimicrobial properties during care, its binding to cellulose in cotton and cotton–polyester blends has been researched, but not to polyester alone. Therefore, the functionalization of polyester fabrics with chitosan by thermosol in the form of submicron particles and pad-dry-curing with homogenized gel was investigated in this work. The functionalization with chitosan was carried out on untreated polyester fabric and polyester fabric activated by alkali hydrolysis. In order to reduce the release of chemical substances during the entire life cycle of textile production, no binder was used. The effects were evaluated by electrokinetic analysis (zeta potential), and the mechanical, spectral, moisture management and antimicrobial properties were determined using standard methods. The functionalized polyester fabrics were submitted to 10 washing cycles in a solution of non-ionic surfactant for determination of its durability. It was shown that the functionalization of hydrolyzed polyester fabric with homogenized chitosan gel by pad-dry-curing results in excellent antimicrobial efficacy and moisture management properties while maintaining the mechanical properties of the fabric even after 10 washing cycles.