Different doses of gamma Irradiation (0Gy, 10Gy, 60Gy, 100Gy and 200Gy) were evaluated as potential treatment to extend the storage period and maintain the quality attributes of onion bulbs (cv. Punjab Noraya) at ambient temperature for a period of 144days. It was observed that storage parameters such as physiological loss in weight, sprouting percentage, rotting percentage and quality traits like total soluble solids, firmness, color parameters, ascorbic acid and pyruvic acid varied significantly (p < 0.05) during storage period with respect to doses of irradiation. No rotting and sprouting were observed upto 24days and 84days, respectively in both gamma irradiated and un-irradiated bulbs. At 5months of storage, the physiological loss in weight varied from 28.5 to 63.6% in all treatments. Physiological weight loss and rotting percentage were higher in the untreated (control) as well as bulbs radiated @ 10Gy and 200Gy. Firmness was better retained in the bulbs irradiated with gamma rays @ 120Gy bulbs upto 84days of storage. However, no clear-cut pattern for colour changes (L, a, b values) was observed with respect to the irradiation doses. TSS in bulbs decreased upto 36days of storage and thereafter increased upto 48th day of storage irrespective of the dose of gamma irradiation. Ascorbic acid content of bulbs decreases significantly in all the irradiation treatments during storage but pyruvic acid initially increased, then decreased and again increased at the end of the storage period in un-irradiated and irradiated treatments. It is concluded that onion bulbs irradiated with gamma rays @ 120Gy resulted in minimum loss in weight, rotting and sprouting while maintained best quality for 3months of storage at ambient storage conditions.