The aim of this study was to analyse the characteristics of patients with rheumatoid arthritis (RA) who make use of alternative or complementary medicine (CM). Two hundred and sixty-two randomly chosen patients with RA filled out self-assessment health status and pain questionnaires. Differences between the group of patients making use of both CM and conventional treatment (n = 52) and the group of patients who relied only on conventional treatment prescribed by their rheumatologists (n = 210) were explored with respect to demographic characteristics, duration of RA, levels of physical, psychological and social functioning, and pain-coping behaviour. We found that female patients used CM more often than did male patients, and those who used CM were younger than those who did not. There were no differences with respect to duration of RA, physical, psychological or social functioning or pain coping; however, the perceived impact of RA on several domains of life was higher in patients who used CM than in those who did not. Nevertheless, the patient groups did not differ in terms of medical consumption, except that those who used CM visited medical specialists for RA-related complaints less than those who relied only on conventional treatments. We concluded that the higher impact of RA, in the absence of worse disease, perceived by users of CM in several domains of life, especially psychosocial functioning, could be the reason they use CM. This suggests that CM cannot be substituted by additional conventional treatment prescribed by the rheumatologist, but rather by psychosocial intervention.