OBJECTIVE: To evaluate the effects of a spouse-assisted pain-coping skills training intervention on pain, psychological disability, physical disability, pain-coping, and pain behavior in patients with osteoarthritis (OA) of the knees. METHODS: Eighty-eight OA patients with persistent knee pain were randomly assigned to 1 of 3 conditions: 1) spouse-assisted pain-coping skills training, (spouse-assisted CST), 2) a conventional CST intervention with no spouse involvement (CST), or 3) an arthritis education-spousal support (AE-SS) control condition. All treatment was carried out in 10 weekly, 2-hour group sessions. RESULTS: Data analysis revealed that at the completion of treatment, patients in the spouse-assisted CST condition had significantly lower levels of pain, psychological disability, and pain behavior, and higher scores on measures of coping attempts, marital adjustment, and self-efficacy than patients in the AE-SS control condition. Compared to patients in the AE-SS control condition, patients who received CST without spouse involvement had significantly higher post-treatment levels of self-efficacy and marital adjustment and showed a tendency toward lower levels of pain and psychological disability and higher scores on measures of coping attempts and ratings of the perceived effectiveness of pain-coping strategies. CONCLUSION: These findings suggest that spouse-assisted CST has potential as a method for reducing pain and disability in OA patients.