The empiric recurrence risk of multiple sclerosis (MS) of relatives of French MS patients is not known. Using a standardized interview, we collected the family histones of 357 consecutive patients followed at our MS clinic; adequate information was obtained on 4784 relatives up to the third degree. Thirty-five patients (9.8%) had a relative with MS. The risk-curve for relatives was the same as in other studies conducted with a similar methodology in Canada. England and Flanders. but the crude overall MS recurrence risk for relatives was lower in France. The genetic burden of MS may be lower in France than in areas of higher MS prevalence.