The present study investigated the effect of GA3 on the physicochemical properties and shelf life of mango (Mangifera indica L. var. Bombay green) from 31st May 2022 to 8th June 2022 at the Central Laboratory of GPCAR collage Gothgaun, Morang, Nepal. The study's goal was to find the right gibberellic acid concentration to use in mangoes that were collected at a mature stage to delay fruit ripening, preserve quality, and lengthen shelf life. The experiment was laid out in a Completely Randomized Design (CRD) with five treatments and four replications. Mature freshly harvested mango fruits of uniform size were dipped into an aqueous solution of gibberellic acid at 0 ppm (T1), 100 ppm (T2), 200 ppm (T3), 300 ppm (T4) and 400 ppm (T5) for 10 minutes. Data on physicochemical parameters (mango pulp pH, total soluble solids, titratable acidity, physiological weight loss, and shelf life) were statistically analyzed through biochemical analyses. Further, fruits treated with 400 ppm of GA3; resulted in the lowest physiological loss in weight (22.08%), the minimum pulp pH (5.02), and the minimum titratable acidity (0.14%) on the 8th day after storage. The highest total soluble solid (19.85°B) was recorded with GA3 @400ppm, while the lowest soluble solids (16.90°B) were recorded with control ppm on the 8th day after storage. Fruits treated with GA3 at 400 ppm had the longest shelf life (7.17 days), while fruits treated with GA at 300 ppm had the shortest shelf life (7.19 days). Therefore, the best results were obtained when gibberellic acid was applied at 400 ppm, which extended the shelf life and physiochemical traits of mango fruits.