Senescence of various cut flowers is characterized by autocatalytic ethylene production from parts of the flower and subsequent wilting of the petals. Previous studies reported that elevated CO2 delayed the onset of autocatalytic ethylene production of cut carnation flowers. In this study, effects of short-term CA and 1-MCP on vase life of cut carnation (Dianthus caryophyllus L.), prairie gentian (Eustoma grandiflorum (Raf.) Shinn), and chrysanthemum (Dendranthema grandiflora Tzvelev) flowers were investigated. Cut flowers were treated for 2 h at 5 degrees C with elevated CO2 concentrations of 10, 15 or 20% with or without 1-MCP and then were placed in water at 23 degrees C to follow senescence. Treatment with short-term CA at 15 or 20% CO2 plus 1-MCP, reduced ethylene production in carnation. Both short-term CA and 1-MCP treatments delayed senescence and prolonged the vase life of cut carnations and prairie gentian for 3 and 2 days compared with 10 and 8 days in untreated controls, respectively. However, these treatments did not affect the vase life of chrysanthemum indicating that this flower was not sensitive to ethylene. It is concluded that short-term CA can decrease ethylene production and prolong the vase life of ethylene-sensitive flowers. More studies should be accomplished for optimizing CO2 level, duration and temperature of CA treatment.