Background and Objective: Dysmenorrhea is the most common gynecologic complaint among adolescent females. They may usually not seek professional expertise in their attempt to alleviate this condition. The aim of this Quasi-experimental study was to determine the effect of group counseling program regarding to nutrition and exercise on primary dysmenorrhea in adolescents at high schools. Methods and Materials: Eighty girls between 14-18 years of age were selected by simple sampling and divided into two groups (test and control). These groups were studied before and after the intervention. Data was collected in both groups based on a questionnaire concerning 24- hour diet, pain quality and severity and nutritional and physical practices. Group counseling was then held over 8 sessions each of which lasted 1.5 to 2 hours for test group. Both groups were followed up for 3 consecutive menstrual periods by a self-report checklist. Finally, they were assessed again at the end of the above study periods. Results: Findings of this study revealed a significant difference in pain severity of primary dysmenorrhea before and after the intervention (P=0.000). A significant difference was also seen in nutrition and exercise status in both groups before and after counseling program (P<0.05). Conclusion: From this study it can be concluded that in order to decrease and prevent the severity of primary dysmenorrhea and improve the nutrition and exercise status, counseling programs are better to be performed in high schools. Key words: Group counseling, Primary dysmenorrhea, Nutrition, Exercise