Background and Objective: Breast cancer is one of the most common types of cancer in Iranian women. The aim of this study was to compare the effectiveness of acceptance and commitment with meaning therapy on quality of life and sexual function in women with breast cancer. Materials and Methods: This study was an experimental study and the study design was a pretest-posttest study with a control group. The statistical population was all patients who refer to Imam Reza Hospital in Kermanshah in 2020 with breast cancer. Thirty patients were selected through purposive sampling and randomly divided into three groups: acceptance and commitment with meaning therapy, meaning therapys and control group. Acceptance and commitment intervention consisted of 8 weekly sessions that were performed in groups for experiment groups. The EORTC QLQ-C30 Quality of Life Questionnaire and Rosen Women's Sexual Function Questionnaire were used. Data analysis was performed using analysis of variance and post hoc test using SPSS Statistics for Windows, version 21. 0 (SPSS Inc., Chicago, Ill., USA). Results: The mean (SD) of the functional scope of quality of life in acceptance and commitment group therapy increased from 34. 6 (3. 3) in the pre-test to 74. 1 (2. 2) in the post-test and in the follow-up phase 72. 4 (3), which had a slight decrease (P<0. 03). In the meaning therapy group, the mean (SD) of the functional scope of quality of life increased from 33. 8 (2. 4) in the pre-test to 41. 2 (3. 3) in the post-test, and in the follow-up phase 39. 3 (2. 1), which had a slight decrease (P<0. 03). In acceptance and commitment group therapy, the mean (SD) of the scope of quality of life symptoms decreased from 69. 1 (3. 3) in the pre-test to 28. 4 (2. 8) in the post-test, and in the follow-up phase, 31. 1 (2. 2), which had a slight increase (P<0. 013). In the meaning therapy group, the mean (SD) of the range of the scope of quality of life symptoms decreased from 63. 2 (2. 2) in the pre-test to 57. 4 (2. 7) in the post-test, and in the follow-up phase, 59. 4 (1. 9), which had a slight increase (P<0. 02). In acceptance and commitment group therapy, the mean (SD) of sexual function increased from 13. 8 (5. 9) in the pre-test to 23. 7 (4. 8) in the post-test and in the follow-up phase 22. 6 (3. 9), which had a slight decrease of (P<0. 02). In the meaning therapy group, the mean (SD) of sexual function increased from 12. 7 (4. 2) in the pretest to 19. 4 (4) in the posttest and in the follow-up phase, 18. 4 (3. 3), which had a slight decrease (P<0. 02). The scores of the control group did not differ significantly in the three phases. Also, acceptance and commitment therapy was more effective than meaning therapy in increasing the functional scope of quality of life (P<0. 03), reducing the scope of quality of life symptoms (P<0. 04), and improving sexual function (P<0. 02). Conclusion: The study showed that both acceptance and commitment with meaning therapy improved quality of life and sexual function in breast cancer patients. Acceptance and commitment therapy had a greater effect on improving quality of life and sexual function than meaning therapy.