Despite the global decline in the standardized mortality rate of multiple sclerosis (MS), recent research on MS patient survival, especially in Taiwan, remains limited. This study aimed to investigate survival, mortality causes, and associated factors among MS patients in Taiwan. The Taiwan National Health Insurance Research Database was used as the primary data source, and a Cox proportional hazard model was employed to estimate and analyze factors related to survival. We analyzed data from 1444 MS patients diagnosed between 2000 and 2018. Age at diagnosis was positively correlated with the risk of death. Among the 190 patients who died, the leading causes of disease-related deaths were nervous system diseases (n = 83, 43.68%), followed by respiratory system diseases and certain infectious and parasitic diseases. The 8-, 13-, and 18-year survival rates for MS patients were 0.97, 0.91, and 0.81, respectively. This study highlights that the MS patient’s socioeconomic status, environmental factors, comorbidity severity, and related medical variables were not significantly associated with survival.