The study analyzed effect of high-intensity interval training (HIIT) containing plyometric exercise on physical fitness and skill performance of U < 17 junior male handball players. The total subject for the study was twenty (20) comprehensive sampling techniques were used and randomly divided between experimental (n = 10) and control (n = 10) groups. During the 8-week intervention, the experimental group performs a combined HIIT with plyometric exercise 2 days a week for a total of 40 minutes. The control group participated in the only regular handball training program. Both the EG and CG participated in selected physical fitness and skill performance field tests before and after training. Repeated sprint run (RSA) test, agility, handball agility test (HAT), countermovement jump (CMJ test), and speed dribbling (obstacle dribble test) were measured. These data were analyzed by using SPSS version 26 software by paired sample t-test and independent-sample t-test with a significance level of 0.05. The analyzed data showed that HIIT containing plyometric exercise significantly improved Repeated sprint run (RSA), agility, and countermovement jump (CMJ) in pre-posttest performance of EG (p < 0.05). But, speed dribbling does not significantly improve in the EG (P > 0.05). In CG no significant improvements were found in all physical fitness and skill variables of pre-posttest performance (P > 0.05). In addition, as assessed by the independent t-test the post-test performance of RSA, agility, CMJ, of EG more significantly improved than the post-test of CG tests (p < 0.05).but not in speed dribbling (p > 0.05). Based on this finding, it can be concluded that 8-week HIIT containing plyometric exercise had a positive effect on RSA, agility, and CMJ, of handball players. Therefore, it is recommended that handball players and coaches should include combined HIIT containing plyometric exercise programs in their training sessions for the physical fitness development of handball players.