Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system affecting approximately 2.8 million people worldwide. In addition to genetic and environmental factors, various lifestyle factors contribute to disease development and progression. We performed a monocentric retrospective study and investigated the effect of lifestyle factors such as obesity, smoking, alcohol consumption, physical activity, and dietary habits on the degree of disability in a cohort of people with MS (pwMS) with an average onset of disease after the age of 55. This late-onset MS (LOMS) study group ( = 47) was characterized by a mean age of 60.9 years and a mean duration of disease of 5.0 years. The LOMS study group was compared with two control groups. The study participants in the "old control group" (C) were on average as old and in the "young control group" (C) as long suffering from MS as the pwMS in the LOMS group. Data from medical documentation and a questionnaire were analyzed using descriptive frequency analyses and testing for correlation between different variables also by generalized estimating equations. The Expanded Disabilty Status Scale (EDSS) score and the progression index were used as a measure of disability. We found a significant association between smoking history and the current EDSS score in the C group, but not in the two older study groups. For physical activity, there was a significant negative correlation with EDSS score in the study group and the C group, alcoholic beverage consumption correlated with decreased EDSS in the C group. The intake of meat negatively correlated with the progression index in the LOMS group. In summary, different life-style factors correlated with disability depending on patient age and disease duration. These life-style factors may be considered in the future counseling of pwMS at older ages.