Background: Menstrual cramps are one of the most frequent problems that adolescents face, and it have a significant impact on females' quality of life. Progressive muscle relaxation is a useful strategy to minimizes menstrual cramps after short, basic training. It is one of the most effective complementary therapies because it is simple to learn, inexpensive, highly useful, and has no negative side effects. Aim: to evaluate the effect of progressive muscle relaxation technique on menstrual cramps among adolescent students. Design: A quasi-experimental research design (pre/post-test) was utilized to achieve the aim of the current study. Setting: The study was conducted at the Faculty of Nursing - Sohag University. Sample: All first-year adolescent students (530) enrolled at the Faculty of Nursing-Sohag University were included in the study. Tools for data collection: Tool I: A structured interviewing questionnaire that consists of two parts; part (1) adolescent students' personal data; part (2) adolescent students' menstrual history; Tool II: Numeric Pain Rating Scale (NPRS). Results: The majority of the adolescent students had mild pain and less than one fifth of them had moderate pain while none of them had severe pain post-progressive muscle relaxation technique application. A highly statistically significant differences in the mean pain scores among the adolescent students pre & post application. Moreover, there is highly significantly decrease the pain score in the post-application compared to pre application of progressive muscle relaxation technique.  Conclusion: Progressive muscle relaxation technique has an impact on reducing menstrual cramps when they are practiced on a regular basis. Recommendations: It is advised that the progressive muscle relaxation technique should be utilized as a supportive therapy to help adolescent girls to alleviate menstrual cramps.