This study evaluated the effect of cognitive-behavioral therapy (CBT) compared with other treatments on improving the quality of life in rheumatoid arthritis (RA) patients. This study was carried out in a rheumatologic referral clinic at an academic hospital. RA patients were categorized in three subgroups: cognitive behavioral therapy group, educational therapy group, and conventional treatment as the control group. Quality of life was assessed with the Arthritis Impact Measurement Scales (AIMS-2) questionnaire. The CBT subgroup (n=30) received cognitive-behavioral treatment with 7 two-hour sessions twice a week; the educational therapy group (n=30) received education about nutrition and osteoporosis, while controls (n=30) received conventional RA medical treatment. Outcomes were gathered in 14 domains of AIMS-2 including activity, walking, pain, self-care, social activity, depression, and anxiety. The 90 studied patients comprised 72 female patients (80.0%) with a mean age of 41.7 years. The degree of improvement in physical activity (p=0.2), hand/finger function (p=0.18), arm function (p=0.28), social activity (p=0.6), satisfaction (p=0.05), household tasks (p=0.9), health perception (p=0.3), self-care ability (p=0.59) showed no significant difference between the three subgroups. Moreover, CBT was effective in improving mood, ability to walking and bend, working, reducing pain and tension, and these effects were independent of age, gender, or education. Additionally, education about nutrition in RA patients improved their ability to work and their mood, and it effectively reduced tension. Based on the findings, CBT is a recommended modality adjunct to RA medical treatment. CBT is specifically beneficial for patients with depressed mood, problems in walking, bending or working, and in subjects who are suffering psychosocial tension.