Etanercept (Enbrel, Wyeth Pharmaceuticals) is a fusion protein composed of a soluble TNF alpha receptor issued from bio-technology. It is a member of TNF alpha's family with two others marked infliximab (Remicade, Scheringh Plough Laboratory), chimeric monoclonal antibody (25 p. 100 mouse) and adalimumab (Humira, Abbott France Laboratory), humanized monoclonal antibody (100 p. 100 human). In United States, etanercept is approved by Food and Drug Administration, since 1998, to treat rheumatoid arthritis showing an inadequate response to prior therapy with other disease-modifying antirheumatic drugs (DMARDS). In France, the MA (Marketing Authorization) is more recent, in 2000, etanercept to treat active rheumatoid arthritis who showed an inadequate response to others DMARDS (like methotrexate for example), with opportunity, in 2002, to administer etanercept in active, severe RA, in first line treatment without previous use of methotrexate. Others MA have been obtained in ankylosing spondylitis (2004) polyarticular-course juvenile rheumatoid arthritis (2000), and in the treatment of psoriasic arthritis (2002). Request of MA have been realised to treat cutaneous mild to severe psoriasis in adult, which failed to respond, contradication or no tolerance with systemic treatment as methotrexate, cyclosporine or phototherapy. Among the others anti-TNF therapy, only infliximab can be prescribed, in dermatology, to treat psoriatic arthritis in France. Encouraging good results were the subject of cases report, but lacking clinical trial, predicting probably administration of etanercept in others indications in future. TNF alpha is a proinflammatory cytokine and plays an important role in the physiopathology of large inflammatory diseases. Logically, in future, we should increased prescription of biotherapy, particularly anti-TNF alpha. We have to mind short or mild-term adverse events, widely described in the literature, but long-term side effects remained unknown. Moreover, these biotherapic agents have a high cost and should be estimate.