'Black Amber' plums were harvested at the commercial stage and treated at the same date of harvest with doses of 0.5 and 1 mu l L-1 1-methylcyclopropene. Fruits maintained at the same conditions without any treatment were used as Control. Fruits were stored at 1+/-0.5 degrees C and 90% RH during 30 days of storage. Effects of 1-MCP on fruit firmness (FF: kg), weight losses (WL: %), titratable acidity (TA: %), and total soluble solids (TSS: %), were determined during 15 and 30 days of storage. The firmness maintained better than Control in both doses of 1-MCP applications, overall quality parameters were enhanced by 1-MCP treatments.