Thirty-five patients with a clinically [1] definite multiple sclerosis (M.S.) were treated in an open trial (1975-1993) with a standard dose preparation of total IgG (5 grams per week) by intra-muscular or intravenous injection. This treatment was used in 35 patients: during 3 to 16 years. Using Kurtzke's disability scale the results were: 1) a significant deterioration (loss of 1 grade in the Kurtzke's disability scale) only 14 years after the entry in the trial. 2) regarding current therapeutic results: improvement for 8 patients, deterioration for 18, and stability for 9. Neither the age at the M.S. onset and at the entry, nor the duration of the disease, nor the disability score at the entry were factors modifying significantly the efficacy of the treatment. The comparison of these results with previous predictive studies (Confavreux, Weinshenker) suggests a significant reduction of M.S. progression, with an increase of the functional independence period. No side-effects were observed, and this immunotherapy, which may be convenient for home care, must be tested in properly controlled trials.