Calisthenics is a form of exercise that aims to increase the body's strength and flexibility using only one’s own body weight as resistance. The purpose of this study was to investigate the effect of calisthenics exercise on health related physical fitness components among Washera secondary and preparatory school students. The study employed experimental research design. 34 male students of Washera secondary and preparatory with the age of (EG=19.76±1.640, CG = 19.71±1.532) had divided randomly into 2 equal groups. Both the exercise group (EG, n = 17) and control group (CG, n = 17) participated in the typical 1 classes of 40-minute Physical education per week in schools, but only EG participated in additional 3 sessions per week of 40 to 60 minutes per session of calisthenics exercise, which comprised as walking, jogging, running and rope skipping. Both groups had taken pre and post-testing and all the subjects participated in physical fitness tests: cardiorespiratory fitness was measured using 12 minute run test body composition, muscular endurance, muscular strength, and flexibility measured by using body mass index (BMI), ninety degree push-up. Chin-up test, and sit & reach test respectively. The data collected from the study subject was analyzed using SPSS version 26 software by paired t-test with level of significant 0.05. The results showed calisthenics exercise significantly improved cardio respiratory fitness (p=0.000), muscular endurance (p=0.000), muscular strength (p=0.001), and flexibility (p=0.002) in EG, significant at (p<0.05). Besides, there were significantly reduced body mass index (p=0.003). But, no significant differences were found in all of the variables in CG cardiorespiratory fitness (p=0.079), muscular endurance (p=0.120), muscular strength (p=0.090), flexibility index (p=0.087) and body mass index (p=0.093) not significant at (p>0.05). Based on this finding, it can be concluded that eight weeks calisthenics exercise has a positive effect on the improvement of health related physical fitness of students.