Influence of 1-MCP application in citrus fruit juice color and vitamin C concentration was determined for `Fallglo' tangerines, `Valencia' oranges, and white `Marsh' grapefruit. MCP was applied at 500 μL·L-1 for `Fallglo', and 1000 μL·L-1 for `Valencia' oranges and `Marsh' grapefruit at 75 °F for 7 hours in a container of 3' × 3' × 3.5' dimension. After three months storage at 40 °F and 93% relative humidity, vitamin C concentration in juice (mg/100 mL) was higher in MCP treated than non-treated `Valencia' oranges (37.1 vs. 30.6) and `Fallglo' tangerines (26.9 vs. 24.0). No difference was found in vitamin C concentration from `Marsh' grapefruit juice either treated (27.9) or non-treated (28.7) with MCP. Forty percent of vitamin C concentration was lost from one month after packing to the third month in storage for white `Marsh' grapefruit. Vitamin C loss was much slower for tangerines in comparison to grapefruit in postharvest. Juice color was not influenced by the MCP application for `Valencia' oranges while Hue and Chroma were improved in treated fruits for `Fallglo' tangerines and `Marsh' grapefruit compared to non-treated fruits. Applying MCP before degreening reduced vitamin C degradation 6 weeks after packing but not at 12 weeks for `Fallglo' tangerines. However, fruit color was improved at 6 and 12 weeks of storage. These results are important for postharvest quality management of citrus fruit and juice.