Background & Objective: Dysmenorrhea is a common problem in young women that affect their activities. Various alternative methods including relaxation have been proposed to manage primary dysmenorrheal. The objective of this research is to study the effects of relaxation on primary dysmenorrhea among first year nursing and midwifery female students at Tehran University of Medical Sciences.

Methods & Materials: This is a quasi-experimental study. The samples (n=80) were randomly assigned in two groups. Experiment group (N=40) received the relaxation technique. Relaxation technique was done twice a day each section lasted 20 minutes for 3 menstruation cycles. The questionnaire on pain measurement were completed in the first, second and third day of cycle. Control group (N=40), completed questionnaire in the same days. Data were analyzed using SPSS software and tested using chi-square, t-test - Willcoxcon and fisher exact tests.

Results: The result showed that relaxation therapy had no significant effect on primary dysmenorrhea in the first (P=0.149) and second cycles (P=0.390) in the Experiment group. It had a significant effect on primary dysmenorrhea in third cycle (P=0.023).

Conclusion: The results showed that relaxation technique is an effective method in reducing the symptoms of primary dysmanorrhea in the young women.