Dysmenorrhea is a widespread phenomenon, affecting mainly young nulliparous women, often inducing difficulties in study or in work. Its pathogenesis involves a release of local vasoconstrictors like Prostaglandins and Leukotrienes. Modern therapy is based firstly on the administration of prostaglandin-Synthetase Inhibitors or Contraceptive Pills, with the aim of reducing the menstrual excess of pain inducing substances. In order to achieve more efficacy, on the basis of the already proven effectiveness of the Non Steroid Anti-Inflammatory Drugs (NSAID)s in this field, we recently set out to prevent dysmenorrhea in a double-blind randomized study with Meclofenamate Sorium and Naproxen Sodium. Through the observation of the drop in Basal Body Temperature which usually precedes menstrual flow, we were able to instruct our patients in the earlier recognition of impending menstrual onset, leading to earlier prevention of Prostaglandin and Leukotriene release. Meclofenamate Sodium in particular led to considerable pain reduction, with very good patient compliance and without significant complications, probably of its additional receptor effect.