As an alternative to chemical fumigation using reagents such as methyl bromide, sweet persimmon was treated with γ-irradiation with the aim of extending the export of persimmon to countries with strict quarantine requirements. 1-Methylcyclopropene (1-MCP) was also employed to prevent the loss of persimmon quality, as treatment by γ-irradiation can cause changes in the firmness and color of the fruit, in addition to physiological injuries. The persimmon quality was assessed at 25℃ over a defined period of retail display following long term cold storage for 60 and 90 day. The persimmon firmness was significantly (p<0.05) decreased following γ-irradiation and display at 25℃ over 2 day, but was dramatically reduced after 3 day display and 60 day cold storage. Although irradiation increased the respiration rate of persimmon after long term storage, it was not significantly (p>0.05) altered at the doses employed herein. In contrast, 1-MCP treatment significantly (p<0.05) improved the persimmon firmness from 1.1 N to 6.0-20.6 N after γ-irradiation treatment and 3 day display and little change in the skin color was observed compared to the untreated samples. The rate of flesh softening was also significantly reduced following 1-MCP treatment.