Degreened Shamouti orange fruits, using a low concentration of ethylene (10 ppm), developed as good a colour as that obtained using concentrations up 40 ppm. Respiration rate and rot development at low ethylene concentrations were similar to those in non-degreened control fruits. However, degreening with high ethylene concentration increased both respiration rate and stem-end rot. The duration of the degreening process was more important for peel colour than the ethylene concentration used; it was not possible to shorten the degreening period by using higher concentrations.