The treatment of the patient with systemic sclerosis has greatly improved in the last ten years, because of two kinds of achievements. A number of drugs have been demonstrated to be active in some disease manifestations like alveolitis, pulmonary hypertension and complicated Raynaud's phenomenon. Some of these drugs namely cyclophosphamide and iloprost await to be confirmed as disease modifying agents. The methodological approach to be made in clinical trials has been defined allowing to correctly analyze the results of published trials and plan future ones.