In recent years, mediators synthesized in the adipose tissue, the so-called adipokines, have been described. They have a hormonal action, regulating appetite and glucose metabolism, but also act as cytokines with effects on the immune system, including effects on autoimmunity. The most important adipokines are leptin, adiponectin, resistin and visfatin, and some of them have been assessed in autoimmune rheumatic diseases, especially systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Studies have shown high levels of leptin and adiponectin in SLE, but correlation with disease activity is questionable. In RA, studies have also reported increased levels of leptin and adiponectin, and correlation with disease activity and joint erosion, but the results are conflicting. This review describes the role of leptin and adiponectin on the immune system, as well as on SLE and RA.