Background: Primary dysmenorrhea, characterized by painful cramps of the uterus during menstruation, affects 45–95% of menstruating women. Dysmenorrhea is the leading morbidity among gynecological disorders and the leading cause of pelvic pain. It affects the physical, psychological, and social status of female adolescents. Aerobic exercises help in reducing pain, relieving stress, elevating mood and improving health. Therefore, the present study aimed to evaluate the effect of aerobic exercises on intensity of primary dysmenorrhea among nursing students. Subjects and methods:A Quasi experimental design was used in carrying out this study. A purposive sample of 100 female students, who divided into two groups control group and (aerobic exercise)performed exercises 3 times a week for 12 weeks (3 subsequent menstrual cycles). The tools used for data collection were: a structured Interview Questionnaire, visual Analogue Scale (VAS), WaLIDD Scale and Moo’s Menstrual Distress Questionnaire (MDQ). Results: female student's age ranged between 18-22 years. Intensity of pain was decreased in aerobic group compared to control group with highly statistical significant difference (p < 0.001). Furthermore, WaLIDD total score was reduced with highly statistically significant differences (p < 0.001) in aerobic vs. control group. Menstrual distress symptoms were improved in aerobic group. Conclusion: Aerobic exercises were effective in reducing intensity of dysmenorrhea and improving menstrual distress symptoms compared to control group. Recommendations: Aerobic exercise therapy can be considered as a non-pharmacological option in the management of primary dysmenorrhea. Enhance student's awareness and knowledge about effect of aerobic exercises by adding this topic into curriculums. Key words: Primary dysmenorrhea (PD), Aerobic exercises, VAS, WaLIDD Scale, Moo’s (MMDQ)