A field study was conducted to investigate the effect of foliar application of GA3 and plant ages on yield and quality of carrot seed. Three different plant ages (20, 30 and 40 days) and four concentrations of GA3 (0, 100, 200, 300 ppm) were considered as treatments in the study. The design of the experiment was two factorial Randomized Complete Block Design with three replications where three different plant ages (20, 30 and 40 days) were comprised as factor- A and four different GA3 concentrations (0, 100, 200, 300 ppm) were considered as factor- B. Results showed that plant age of 30 days was found to produce highest seed yield (1152 kg ha-1) followed by 1051 kg ha-1 from 40 days plant age while the lowest seed yield (916.6 kg ha-1) was harvested from 20 days plant age. On the other hand, the highest seed yield (1849 kg ha-1.) was obtained from foliar application with 200 ppm GA3 followed by 300 ppm GA3 (1267 kg ha-1.). The lowest seed yield (106.2 kg ha-1.) was obtained from the control treatment (no application of GA3). The highest yield was obtained (2120 kg ha-1) from the plots having effect of 30 days plant age with 200 ppm of GA3 application. It was statistically/interaction similar to those plots (1924 kg ha-1) of 40 days plant age combined with 200 ppm GA3 application. The lowest seed yield (102.1 kg ha-1) was harvested from the plots of 20 days plant age without GA3 treatment. The study revealed that 30 days plant age with foliar application of GA3 at 200 ppm produced the best quality and the highest seed yield (2.12 t ha-1) in the tropical carrot variety Bejo shetal.