Twenty-four HLA-antigens coded by loci A and B were determined serologically for 60 multiple sclerosis patients from Northern Finland. Forty-five of the patients were also typed by mixed leucocyte culture reactivity for HLA-Dw2. The only statistically significant difference in antigen frequencies in these patients compared with those in controls was the decrease of HLA-A2 among patients. Measles and rubella antibody titres in patients with and without HLA-Dw2 and HLA-B7 antigens were compared using a sensitive radioimmunoassay method. There was no difference between age- and sex-matched patient groups.