The climacteric nature of peach fruit entails its ongoing biological activity, including respiration, transpiration, and other biochemical processes even after harvest, leading to rapid quality deterioration. In an effort to mitigate softening and maintain peach fruit quality, the effectiveness of postharvest dip treatment with sodium nitroprusside (SNP) at concentrations of 0.5mM, 1.0mM, and 2.0mM was explored on ‘Shan-i-Punjab’ peaches during storage at 0-1°C and 90-95% relative humidity for 40 days. The application of sodium nitroprusside to ‘Shan-i-Punjab’ peach fruits exhibited notable benefits, including reduced mass loss, retained firmness, suppressed polyphenol oxidase (PPO) activity, lowered malondialdehyde (MDA) content and relative electrical conductivity (REC), and sustained levels of soluble solids, titratable acidity, total phenolics, ascorbic acid, total carotenoids, and antioxidant activities. This treatment effectively conserved the fruit quality for an extended period during storage. Furthermore, sodium nitroprusside treatment demonstrated a softening reduction by inhibiting the activities of cell wall wall-degrading enzymes such as pectin methylesterase, polygalacturonase and cellulase. Among the various concentrations tested, the SNP1.0 mM concentration proved to be the most effective in reducing fruit softening and extending the storage life of peaches up to 30 days under cold storage conditions.