Exposure to hypoxic O2 levels has been reported to result in better epidermal color, higher titratable acidity and soluble solids levels, delayed softening and reduced ethylene production and respiratory activity in many fruit species. Mangoes have been shown to tolerate short term (4 days) exposures to O2 concentrations below 0.5% with beneficial effects on firmness retention and maintenance of ground color. In the present work, `Haden' mangoes were stored for 14 days at 15°C with O2 levels ranging from 2% to 5% and compared to an air control and an atmosphere of 25% CO2 in air. `Tommy Atkins' mangoes were stored under the same treatments at 12°C for 21 days. After storage at 12 or 15°C the mangoes were transferred to air at 20°C for 5 days. Ethanol production rates during controlled atmosphere (CA) storage were significantly higher at O2 levels of 4% and below. Respiration (CO2 production) rates were reduced during CA storage but did not differ from the control after transfer to air. There were no differences in ethylene production as well as in flesh firmness, titratable acidity and total sugars. The ground color of mangoes kept under the lowest O2 concentration and under 25% CO2 was greener, as indicated by higher hue angles, than in the other treatments upon transfer to air at 20°C. However, only the mangoes stored under high CO2 maintained higher hue angles during the subsequent 5 days at 20°C.