In the present work, peach was chosen as a model to shed some light on the physiological role of JAs during fruit ripening and the reciprocal relationship between ethylene and JAs. The natural derivative of jasmonic acid, MJ, and its synthetic analogue n-propyl dihydrojasmonate (PDJ) were applied to peach fruit at different developmental stages under field conditions, and the following were analysed: (i) time-course of ethylene production and fruit quality; (ii) transcription of PpAOS1 and changes in JA levels; (iii) comparative transcriptome profiling of MJ-treated versus control fruit at harvest; and (iv) expression patterns of some JA-responsive genes following treatments.