The experiment was conducted to determine the effect of gibberellic acid and Naphthalene acetic acid on growth and yield of cucumber at Horticulture Research Field, Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj during mid March- mid June 2021. Total Nine treatments were tried and replicated three times in a Randomized Block Design. Treatments include two growth regulators having concentrations of GA3 (15, 25, 35, 45 ppm) and NAA (75, 100, 125, 150 ppm) and Control (Water spray) were spayed at two leaf stage and four-leaf stages. The application of plant growth regulators significantly effects the vegetative as well as reproductive attributes of the crop. The treatment T3 25 ppm GA3 at 2, 4 leaf stage was found most effective among all the treatments in terms of Vine length at 20, 40, 60 days after sowing (39.12, 91.02, 180.32 cm) Days to first appearance of male flowers in 50% plants (32.86 days), Number of fruits per plant (12.20), Average fruit yield per plant (1870.37 g), fruit weight (153.33g) where as Days to first appearance of female flowers in 50% plants (38.93) and Days to first harvest (50.6) was observed in 35 ppm GA3, length of the fruit (14.66 cm in 15 ppm GA3), fruit diameter (4.28 cm in 15 ppm GA3), Average yield (18.77 t/ha in 25 ppm GA3). Based on these observations spraying of GA3 25 ppm at 2, 4 leaf stages was found effective for growth and yield of cucumber compared to other concentrations of GA3, NAA and control.