Introduction: Happiness is one of the psychological needs of mankind and one of the most important and affecting issues in life. The purpose of this study was to determine the effectiveness of "quality of life" group training on the happiness of female teachers. Methods: This study was quasi-experimental with pretest-posttest design and follow-up with control group. The statistical population of the study was all married and employed female teachers in Abhar in the academic year 2017-2018. Thirty of them were selected by systematic random sampling and were randomly divided into two equal groups. Data were collected using the “ Oxford Happiness Questionnaire” . Content validity and reliability of the questionnaire were measured by Cronbach's alpha. The intervention group received eight 90-minute sessions on "quality of life treatment". Completed as pre-test, post-test and follow-up. Data were analyzed by SPSS. 24. Results: In pre-test, post-test and follow-up between intervention and control groups in life satisfaction (F = 5. 67, P <0. 01), positive mood (F = 5. 46, P <0. 01), Health (F = 8. 92, P <0. 01), Efficacy (F = 10. 15, P <0. 01), Selfesteem (F = 7. 21, P <0. 01), Total Happiness Scale (F = 14. 09, P <0. 01) There was a significant difference. Conclusions: "Quality of life treatment" increased the happiness components of female teachers, and this increase was sustained over time. Therefore, it is suggested that counselors and therapists can use this approach to increase happiness.