Introduction: The present study aimed to assess the effectiveness of Acceptance and Commitment Therapy (ACT) compared to Cognitive-Behavioral Therapy (CBT) on the patients' quality of life with chronic back pain. Materials and Methods: The statistical population consisted of all patients with chronic back pain referred to the pain clinic of Akhtar Hospital in Tehran, Iran, in 2021. Thirty patients were selected and randomly assigned to two groups of CBT and ACT. Due to the drop in the sample, finally, ten patients remained in each group. The Personal Well-being Index-Adults (PWI-A) to assess the quality of life was used to collect data. The data were analyzed using descriptive statistics and Wilcoxon and Mann-Whitney U non-parametric tests. Results: The findings showed that both interventions increased quality of life, while the difference between the two interventions was not significant (Z= -1.32, P> 0.05). Although according to Z-scores (-1.84 versus -1.17), ACT was more effective than CBT. Conclusion: Based on the findings, both acceptance and commitment therapy and cognitive-behavioral therapy improve well-being and quality of life in patients with chronic low back pain.
