Dysmenorrhea is pelvic pain usually, associated with menstrual periods. The purpose of the current study is to study the effect of fennel on relieving primary dysmenorrhea compared to vitamin E. Design: A quasi-experimental design was used. Setting: Faculty of Nursing, Benha University. Sampling: A Purposive sample included 116 students divided into two equal groups (58 fennel and 58 vitamin E groups). Instruments: 1- A structured interviewing questionnaire sheet consisted of four parts. 2- Visual Analog Scale. Results: One month before fennel and vitamin E interventions, female nursing students who had severe menstrual pain, lumbo-sacral backache, pain radiating down anterior thigh and breast tenderness were 34.0% & 38.6%, 84.9% & 91.2%, 54.7% & 54.4, 73.7% & 24.6%. Besides at -3rd month follow-up, female nursing students who had no (menstrual pain, lumbo-sacral backache, pain radiating down anterior thigh and breast tenderness) were 41.5% & 19.3%, 50.9% & 28.1%, 77.4% & 61.4%, 94.3% & 87.7% respectively. Conclusion: Fennel tea and vitamin E had strong positive effect on dysmenorrhea relief. But students who received fennel seed's tea experienced less severe dysmenorrhea than students who received vitamin E. Recommendation: nurse should encourage females with dysmenorrhea to try Fennel tea or vitamin E for four subsequent menstrual cycles to ensure their efficacy on dysmenorrhea relief (starting from two days before menstrual bleeding onset to three days after menstrual bleeding onset).