INTRODUCTION: Primary dysmenorrhea (PD) is a painful menstruation due to contractions in the uterus that induce ischemic pain associated with normal pelvic anatomy. OBJECTIVE: The purpose of the study is to evaluate the effect of High TENS application (root level) among adolescent girls of PD. METHODOLOGY: 140 adolescent girls were included with 14-19 years of age and randomly allocated into two groups of Experimental and Control group. The measurement of lower abdominal pain, referred low back pain, and referred bilateral thighs pain was performed by numerical pain rating scale and measurement of systolic as well as diastolic blood pressure by aneroid sphygmomanometer. The data collection was done before and after the intervention. RESULTS & CONCLUSION: There were highly significant difference in intragroup and intergroup comparison of all the outcome variables in group A (p value < 0.001). The study concluded that High frequency TENS application at root level show significant improvement for managing primary dysmenorrhea.