The aim of this study was to evaluate the roles of plant growth hormone (PGH); 2, 4-D to delay tomato fruit ripening under laboratory conditions so as to improve its shelf life and prevent its postharvest loss before reaching consumers. The experimental design was complete random design with three treatment levels of unripe healthy tomato immersed in (30, 50 and 100ppm) of 2, 4-D. The control fruits were immersed with distilled water. All treatments were done in three replications. Quality parameters that serve as indicators of ripening stages such as weight loss, pH, titratable acidity, total soluble solid, pigments (chlorophyll a, chlorophyll b and total chlorophyll), lycopene, total carotenoids, reducing and total sugars were measured over three weeks on weekly basis. Results showed that almost all measured parameters were significantly affected by the application of 2, 4-D; 2, 4-D was found to prevent quality deterioration and rapid ripening of tomato fruits. The effectiveness of PGH appeared to be high at their lower concentrations. Therefore, 2, 4-D may be useful at lower concentrations to delay ripening of tomato fruits and avoid rapid postharvest loss if applied on healthy unripe tomato fruits. However, their impact on other nutritional aspects and human health must be further investigated before application.