A disproportionate number of California multiple sclerosis patients were found to be of Northern European ethnicity. Sevierity of the disorder was associated with present age, male gender, age at diagnosis, and years since diagnosis. Age at diagnosis was associated with present age, Northern European ethnicity, greater geographical latitude at the time of birth and at the time of diagnosis, and number of years since diagnosis. In contrast to findings in Denmark and Sweden, the present study did not find a disproportionate number of multiple sclerosis patients to have been born in spring and summer months. An incidental and unexpected finding was that about seven percent of multiple sclerosis patients were found to be at least part Native-American, an ethnicity previously regarded to have a very low prevalence of multiple sclerosis.