Preconditioning is a thermal treatment that consists in maintaining stone fruits immediately after harvest and prior to cold storage at 20 C for 24–48 h in special chambers aimed to extend fruit market life reducing chilling injury symptoms. This work investigates whether preconditioned ‘September Sun’ peaches had better eating quality than control fruit. Commercially harvested peaches were preconditioned and transferred to cold storage for 12, 26 and 40 days and evaluated for sensory characteristic perception after a ripening period at 20 C. Acceptability of preconditioned fruit was higher than control fruit during this 40-day coldstorage period. Preconditioned and control fruit were also segregated into two clusters by PCA analysis; preconditioned fruit clustered together and show association to acceptability, sweetness and juiciness, while the second cluster was associated with flesh texture, acidity and aroma, suggesting the positive effect of preconditioning on final fruit quality. Preconditioned fruit maintained their sensory characteristics longer than control fruit during this 40-day cold-storage period. This work has been supported by the research project ‘Consolidación del mejoramiento genético de duraznero a través de la selección de variedades orientadas a satisfacer al consumidor of Innova-Chile, CORFO.