Background & Objectives: Regarding to high incidence of dysmenorrhea and influence on daily activities and fewer side effects of herbal medicines than chemical drugs, the aim of this study was to compare the effect of mefenamic acid and matricaria chamomilla (MC) on primary dysmenorrhea.

  Methods: This triple-blind randomized clinical trial study was done on 90 female students residents in dormitories of Kashan University of Medical Sciences in 2012. The subjects were categorized into two groups randomly. Mefenamic acid capsules (250 mg, every 8 hours) were given to the first group from 48 hours before menstruation until 24 hours after it. The second group received MC capsules made in Barij Essence Factory of Kashan (250 mg, every 8 hours). Severity of dysmenorrhea was measured by McGill ruler. Finally, the data were analyzed by SPSS. The chi-squire, fisher and paired t-test were used. The p-value of less than 0.05 was considered as statistically significant difference.

  Results: The result of this study indicated that both chamomilla and mefenamic acid can reduce the severity of pain and hemorrhage (p<0.05) but there was no significant difference between two groups (p>0.05).

  Conclusion: This study showed that matricaria chamomilla is effective in decreasing the severity of primary dysmenorrhea and reducing hemorrhage as well as mefenamic acid.