Background: Adolescents’ behavioral and emotional disorders denote a considerable public health problem in developing countries. Hence, positive psychology intervention plays a prominent role in promoting mental health and increase happiness among adolescents. This study aimed to evaluate the effect of positive psychology intervention for promoting mental health, life satisfaction, and happiness level among adolescents. Method: A quasi-experimental research one group pre-test and post-test design were used with baseline data collected from second and third-year preparatory students from Saris Alliyan Aljadida preparatory school, Menoufia governorate, Egypt. Seven instruments were utilized; a constructed interview questionnaire, Brief Symptom Inventory, General Self-Efficacy Scale, Life Orientation Test-Revised, Rosenberg Self-Esteem Scale, Satisfaction with Life Scale, and The Oxford Happiness Questionnaires. Result: the current study's findings proved there were significantly greater increases in self-efficacy, self-esteem, optimism, and life satisfaction scores from pre-intervention to post-intervention. Also, there was significantly greater increases in happiness level from pre-intervention to post-intervention. Conclusion: This study showed the importance of the application of positive psychology intervention for promoting mental health and increase life satisfaction and happiness levels among adolescents. Recommendation: Based on the study's findings, it was recommended the school nurse regularly assess all adolescents to identify those with low levels of happiness and life satisfaction. Also, the school nurse applies positive psychology intervention to prevent depression, promote mental health and increase life satisfaction and happiness levels among adolescents in the school setting. How to Cite this Article Pubmed Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among SRP. 2020; 11(10): 996-1008. doi:10.31838/srp.2020.10.149 Web Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among http://www.sysrevpharm.org/?mno=43681 [Access: March 30, 2021]. doi:10.31838/srp.2020.10.149 AMA (American Medical Association) Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among SRP. 2020; 11(10): 996-1008. doi:10.31838/srp.2020.10.149 Vancouver/ICMJE Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among SRP. (2020), [cited March 30, 2021]; 11(10): 996-1008. doi:10.31838/srp.2020.10.149 Harvard Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy (2020) Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among SRP, 11 (10), 996-1008. doi:10.31838/srp.2020.10.149 Turabian Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. 2020. Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among Systematic Reviews in Pharmacy, 11 (10), 996-1008. doi:10.31838/srp.2020.10.149 Chicago Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. Positive Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among Adolescents. Systematic Reviews in Pharmacy 11 (2020), 996-1008. doi:10.31838/srp.2020.10.149 MLA (The Modern Language Association) Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy. Positive Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among Adolescents. Systematic Reviews in Pharmacy 11.10 (2020), 996-1008. Print. doi:10.31838/srp.2020.10.149 APA (American Psychological Association) Style Amal A. El-Abbassy, Alyaa Hosam El Din Salam, Kariema I. EL Berry, Reda Elfeshawy (2020) Psychology Intervention for Promoting Mental Health, Life Satisfaction and Happiness Level among Systematic Reviews in Pharmacy, 11 (10), 996-1008. doi:10.31838/srp.2020.10.149