Numerous clinical trials have been performed during the last 5 years in multiple sclerosis patients. Some of the results have been encouraging. However, clinical benefit remains limited. Corticosteroids are indicated during the course of severe relapses but have not proven any long term benefit. Immunosuppressive agents may be of some help during very active stages of the disease. Results of interferon beta-1b trial in relapsing multiple sclerosis have shown a moderate decrease in the frequency of relapses. The same effect has recently been reported with interferon beta-1a. In addition, an effect on disability progression have been suggested with the latter interferon. In France, interferon beta-1b is now authorized in the relapsing forms of the disease. Initial results with copolymer I also suggest an effect on the frequency of relapses. Despite these major therapeutical efforts, further trials, possibly using new therapeutical approaches, are still needed.