Correlation of Softening and Polyamines levels during the Controlled Atmospheres Storage of Avocado were examined. The fruit was harvested then stored for 9 weeks at 0oC in Controlled Atmospheres (CA) containing 2.5, 7.5 % O2 with 5 and 10 % CO2 in all combinations (4 mixtures) and air (20 % O2). The incidence of CI, textural change and polyamines concentration, rates of respiration, ethylene production was determined. Fruit stored for 9 weeks in 2.5 % O2 and 10 % CO2 softened after transfer to air while fruit from other mixtures containing 10 % CO2 did not soften. The polyamines concentrations were high on the day fruit were transferred from 0oC to 28oC after storage 3, 6 and 9 weeks and subsequently decreased during the ripening stage at 28oC. Polyamine concentrations in CA stored avocado were higher than those in air stored fruit. After 9 weeks of storage in CA at 0oC then transferred to air resulted in a slight increase in putrescine (PUT), a slight increase in spermidine (SPD) and a major decrease in spermine (SPN). Low oxygen concentration (2.5 %) at 0oC storage induced higher levels of polyamines and significantly inhibited the softening of fruit compared to fruit stored in air (20 % O2). Following 3 weeks storage at 0oC no indication of CI in all treatments after ripening for 6 days, but was light discoloration after 6 and 9 weeks storage and very severe in air storage. The rate of respiration and ethylene production of fruit stored in air were higher than those of fruit stored in CA treatments.