The ultrasound-assisted extraction process with microwave pretreatment was modeled and optimized to maximize the yield of antioxidants from green walnut husks using a response surface methodology with Box-Behnken design. In this design, the ultrasound-assisted extraction time (10-40 min), ultrasound-assisted extraction temperature (40-60 °C), and microwave pretreatment time (20-60 s) were selected as the factors, while the total antioxidant content was defined as the response. The solvent of choice for extracting antioxidants was 50% (