Background and aims: Chronic pain is a common health problem that affects various aspects of life. Acceptance and commitment therapy (ACT) seems to be helpful in improving the quality of life and pain catastrophizing in patients with chronic pain. The purpose of this study was to compare the efficacy of ACT and physiotherapy on quality of life and pain catastrophizing in patients with chronic pain. Methods: The subjects were 75 women suffering from chronic pain who were considered for physiotherapy. They were randomly divided into 3 groups including ACT, physiotherapy, and control groups. The control group consisted of 25 patients who were on the waiting list for physiotherapy. The first group participated in 8 sessions of ACT, the second group attended 10 sessions of physiotherapy, and the control group received no treatment. The Pain Catastrophizing Scale (PCS) developed by Sullivan et al and the World Health Organization Quality of Life (WHOQOL-BREF) questionnaire were used in this study. Results: The results showed that the quality of life in the ACT group was significantly higher than that in the physiotherapy group and control group (P < 0.001). Moreover, there was no significant difference between the ACT and physiotherapy groups in reducing pain catastrophizing (P > 0.05), while this difference was significant between the ACT and control groups (P < 0.001). Conclusion: In general, ACT leads to a reduction in pain catastrophizing and an increase in the quality of life of patients with chronic pain. Therefore, beside the current therapy like physiotherapy, ACT can be used as another therapeutic choice for patients with chronic pain.