Acetylene (released from calcium carbide) induced early climacteric along with increased rate of respiration in Alphonso mangoes. However, flavour which is an important quality attribute, was found to be impaired. There was lower synthesis of aromatic components, sugars, and lipids. The metabolism of labelled organic acids and incorporation of labelled linoleic acid into the volatile fraction were suppressed in treated fruits. The degree of unsaturation of free fatty acids increased during ripening and was higher in the control than in treated fruits at their ripe stage. The peel colour with higher carotenoid content was superior in treated compared to untreated fruits. Xanthophylls were higher in concentration in control fruits, whereas, xanthophyll esters and ?-carotenoids were predominant in treated fruits. In treated fruits, the loss of membrane integrity, starch, and pectin were accelerated and there was more rapid dissolution of starch granules as seen under the scanning electron microscope.