Fresh walnut kernels (FWKs) are appreciated because of their unique flavor; however, maintenance of FWKs is still restricted because of their short storability, and there is little knowledge about the storage of this commodity. The effects of walnut green husk extract (WGHE) and ascorbic acid (1%; AA) on the quality of FWKs were investigated during postharvest storage at 4 ± 1 °C for 60 d. The kernels were disinfected with chlorine dioxide (ClO2) and then six aqueous treatments were applied, i.e., 150 mg L−1 WGHE (E150), 300 mg L−1 WGHE (E300), AA 1%, E150+AA and E300+AA. Distilled water was used as a control. Total antioxidant capacity and total phenol were higher in kernels treated with AA; however, E150 and E300 treatments prevented the increase in peroxide value, PPO activity, browning, and microbial growth, and preserved sensory quality attributes during storage. According to the results of this study, WGHE can extend the shelf-life of FWKs while maintaining their quality.