We estimated survival probability and excess death rates for patients with multiple sclerosis (MS) on the basis of data from the Danish Multiple Sclerosis Registry, which includes virtually all patients diagnosed with MS in Denmark since 1948. We reviewed and reclassified all case records according to standardized diagnostic criteria. By linkage to the Danish Central Population Registry and the National Registry of Causes of Death complete follow-up of all MS patients was achieved, with the exception of 25 patients who had emigrated. A total of 2300 of the 6727 MS patients included in the study had died before the onset of the disease was 28 years in men (compared with 40 years in the matched general male population) and 33 years in women (versus 46 years). The excess death rate between onset and follow-up (observed deaths per 1000 person-year minus the expected number of deaths in a matched general population) was 14.3 in men, which was significantly higher than in women (12.0). Excess mortality increased with age at onset of MS in people of each sex. The 10-year excess death rate has decreased significantly in recent decades. Excess mortality was highest in cases with cerebellar symptoms at onset.