In a study involving 35 patients (aged: 16-23 years old) with severe primary dysmenorrhea, mefenamic acid was administered every 8 hours for a maximum of 3 days during menstruation for 3 consecutive cycles. A total of 194 treated cycles could be assessed; 110 cycles with mefenamic acid and 84 with placebo. The results demonstrated that mefenamic acid led to complete relief of all the symptoms of dysmenorrhea in 88.6% patients in all 98 treated cycles. In 2 patients, moderate relief was reported in 5 of the 6 cycles. On the other hand, in patients who were given placebo, only 5 (13%) experienced moderate to slight relief in 11 of the 15 cycles. Thus, it could be stated that mefenamic acid appears to be an effective option with a favorable safety profile for the relief of primary dysmenorrhea.