Despite the well-established antidiabetic effects of zinc oxide nanoparticles (ZnO), there remains a contentious debate surrounding their prooxidant and antioxidant properties. Chlorogenic acid (CGA), known for its potent antioxidant and antidiabetic effects, is hindered by its high cost and instability. In 2022, the synthesis of ZnO/CGA nanoparticles composite demonstrated remarkable antimicrobial and antioxidant properties, particularly effective against COVID-19 which is well Known as diabetes inducer. Consequently, the study's primary objectives were to employ a straightforward method to isolate CGA from coffee beans and subsequently synthesize ZnO/CGA nanoparticles. The secondary objective involved a comparative assessment of the antioxidant and antidiabetic effectiveness of ZnO/CGA-NPs against CGA, ZnO, and a ZnO/CGA mixture. Method: The extraction of CGA from green coffee seeds, utilizing a non-alcoholic method, yielded a notable 3.35% CGA. The resulting ZnO/CGA nanoparticles exhibited an aggregated structure, with CGA firmly attached to the ZnO surface through hydrogen bonds. Notably, while ZnO/CGA NPs displayed antioxidant properties slightly inferior to CGA alone, they successfully alleviated the prooxidant impact associated with ZnO. Moreover, the ZnO/CGA-NPs exhibited the highest inhibitory effects on α-amylase and α-glucosidase. This inhibitory action was attributed to the binding of ZnO/CGA on the allosteric sites of these enzymes, inducing alterations in their 3D geometric structures. In conclusion, the non-alcoholic CGA extraction method, yielding a substantial CGA percentage, presents an easily accessible procedure. The resulting ZnO/CGA-NPs emerge as a promising and effective antidiabetic compound with a moderate antioxidant effect, showcasing their potential in addressing diabetes and associated complications.