Background: Premenstrual syndrome (PMS) is a disorder with physical, psychological and behavioral changes frequently occurs in the luteal phase of women and causes frustration and dysfunction in daily relations with others. Therefore, this study was performed to evaluate the impact of group cognitive- behavioral instruction on decreasing headache, gobbler, tender breast, abdominal bloating and extremities edema .

  Material and methods: In this quasi- experimental study, in a definite region of Tehran, 56 mothers of preschool children who were suffering from this syndrome were selected by volunteer sampling and randomly divided to experimental (n=26) and control (n= 30) groups. Experimental group received 10 sessions of cognitive– behavioral instruction.

  Results: Cognitive- behavioral instruction had a significant impact on physical symptoms, including headache, abdominal bloating and gobbler, but tender breast and extremities edema were not improved.