HLA-A, -B, -C, -DR, -DQ antigens were studied in 43 multiple sclerosis (MS) patients with clinically definite remittent sclerosis from Asturias (North Spain). The prevalence of HLA-B7, B7 and B27 were significantly increased in MS. HLA-B35 was under-represented in these patients. DR2 was increased but not significantly. No association with DQw1 was discovered. The existence of several susceptibility factors in the more common B7/DR2/DQw1 haplotype is discussed.