The purpose of this study was to examine the effect of transcutaneous electrical nerve stimulation(TENS) in the patients of dysmenorrhea. A total of thirty subjects were assigned randomly to one of the two experimental groups or to a control group : 1) an Experimental group I received high-frequency TENS(100pps with a 100-microsecond pluse width), 2) an Experimental group II received low-frequency TENS(2pps with a 100-microsecond pulse width), 3) a Control group received medication(Acetaminophen 600mg). All subjects completed visual analogue scale(VAS) pre-treatment; after post-treatment; 1, 2, 3, 4, and 6 hours post-treatment; and the next morning. The results of study were as follows; 1. The mean pain scores decreased in thru groups. 2. The experimental group II and the control group exhibited a significant decrease in pain post - treatment. 3. The experimental group I had the pain relief obtained after three hours post - treatment. The experimental group II had the pain relief obtained immediately after the post - treatment Control group had the pain relief obtained immediately after the post - treatment, but increased pain after four hours of post-treatment. Finally. this result suggests that TENS can reduce significantly the pain of dysmenorrhea. Besides. low-frequency TENS provided a good result to the excellent subjective pain relief in the subject, compared with high-frequency TENS and medication.