Fruit of cv. Monthong durian (Durio zibethinus) were treated with 0 (control) or 500nLL −1 1-MCP for 12h at 25°C. Fruit were then stored at 15°C. To determine storage life, every 3 days a batch of fruit was transferred to 25°C. The time to ripeness (adequate eating quality) at 25°C in controls (no 1-MCP) decreased from 5 days in freshly harvested fruit to 3 days after 18 days of storage at 15°C. Storage life was considered adequate if the time to ripeness was ≥3 days. The storage life at 15°C of control fruit (no 1-MCP) was therefore 18 days. After the 1-MCP treatment the time to ripeness at 25°C was 7 days in fresh fruit, while in fruit stored at 15°C for 30 days it was about 3 days. The storage life at 15°C of 1-MCP-treated fruit was therefore 30 days. Pulp firmness and pulp total soluble solids (TSS) were determined after 3 day storage intervals at 15°C and when the fruit was ripe at 25°C. These parameters were only slightly affected by the 1-MCP treatment. Furthermore, 1-MCP had no effect on pulp color, but delayed yellowing of the fruit exterior. It is concluded that treatment with 1-MCP before storage at 15°C extended storage life from 18 to 30 days.