Mechanical damage is a major factor contributing towards the postharvest losses of plantain fruit. This study investigated the effects of maturity, genotype, and damage on the ripening period of three genotypes of plantain (AAB), in both ambient tropical (Ghana) and controlled environmental conditions (U.K.). It was found that there were no differences among the genotypes studied. The most mature fruit at harvest ripened the most rapidly, but maturity had no effect on % moisture loss of fruit. At an ambient tropical relative humidity (RH) of between 70 and 96%, only abrasion significantly increased the rate of fruit ripening. Abrasion significantly increased fruit moisture loss and reduced the ripening period of the least mature fruit by up to 39% compared with the control. In the controlled environment, at 100% RH, impact and abrasion had no effect on the ripening period of plantain fruit; however, at between 55 and 65% RH, abrasion significantly increased the rate of moisture loss and caused fruit to ripen significantly more rapidly than impacted and control fruit. It was concluded that abrasion accelerated the rate of ripening of plantain fruit at humidities below 100% RH, by increasing the peel permeability to water vapour. This exposed the fruit to an increased water stress which initiated early ripening.