Investigators in the USA carried out a systematic review of the literature examining the efficacy of psychological interventions (e.g. relaxation, biofeedback and cognitive-behavioural therapy) in the treatment of rheumatoid arthritis (RA). Studies that met the following criteria were included: random assignment, wait-list or usual care control condition; publication in peer-reviewed journals; treatment that included some psychological component beyond simply providing education information; and separate data provided for patients with RA if subjects with conditions other than RA were included. Two investigators independently extracted data on study design, sample size and characteristics, type of intervention, type of control, direction and nature of the outcome(s). Twenty-five trials met the inclusion criteria. Methodological quality was assessed, and effect sizes were calculated for six outcomes. Significant pooled effect sizes were found post-intervention for pain (0.22), functional disability (0.27), psychological status (0.15), coping (0.46), and self-efficacy (0.35). At follow-up (averaging 8.5 months), significant pooled effect sizes were observed for tender joints (0.33), psychological status (0.30) and coping (0.52). No clear or consistent patterns emerged when effect sizes for different types of treatment and control conditions were compared, or when higher quality trials were compared with lower quality ones. Findings do, however, suggest that these psychological interventions may be more effective for patients that have had the illness for a shorter duration.