Rheumatoid arthritis (RA) is a chronic rheumatic disease of unknown aetiology and variable severity. It is now well known that several risk factors are involved in its pathogenesis, including genetic factors and sex hormones as well as environmental factors, i.e. infections and stress. In particular stress is now recognised as an important risk factor for the onset and even more for the modulation of disease activity in RA. Many studies have clearly shown that chronic mild stress (family or professional stress) may lead to proinflammatory effects, increasing disease activity. Furthermore, a positive correlation between the stress level at the onset of RA and radiological progression could be demonstrated. The onset of RA was associated with moderate stress at work, underlining the possible interactions between the various stress systems and the immune system. In this respect it could be demonstrated that coping strategies reduce stress episodes and change stress management with a positive impact on disease activity in RA. However, more studies are warranted to further explore the pathophysiological implications of stress on onset and activity of chronic autoimmune diseases.