The overall aim of this project was to evaluate the impact of socioeconomic factors on different aspects of multiple sclerosis (MS). There is substantial evidence that individuals with low socioeconomic status (SES) have poorer health conditions in general, compared to those with higher SES. This is also seen in welfare states traditionally marked by commitment to social equality, such as the Nordic countries. MS occurs with greater frequency in high-income nations, and some studies have concluded that there is a tendency for higher susceptibility to MS in households of greater affluence. The evidence for a social gradient in risk for MS in a multinational review is however inconsistent. The influence of socioeconomic status on progression in MS is sparsely investigated. To identify potential risk factors for disease severity and progression is of great importance in the treatment of MS. Several studies report an impact of socioeconomic factors on access to disease modifying treatment (DMT) in MS, with a trend of less access to more deprived persons. The first paper aimed to explore the trends in prevalence and incidence of multiple sclerosis (MS) in Telemark county, Norway, over the past two decades, with focus on differences between rural and urban areas. We found a prevalence of MS in Telemark among the highest ever reported in Norway, consistent with an increasing incidence in the county over the past twenty years. We also found a higher prevalence in the rural areas that is unlikely to be explained by possible risk factors like latitude, exposure to sunlight and diet. For paper II and III we used an MS registry of a near complete and geographically well-defined population, combined with data from Statistics Norway. In paper II we found higher maternal level of education in people with MS’ (pwMS) adolescence associated with less pronounced disease progression. High maternal education was also associated with younger age and lower EDSS at disease onset, as well as shorter time from onset to diagnosis. Paper III confirmed that socioeconomic factors had some impact on access to disease modifying treatment (DMT). People with the highest levels of education were more likely to be ever treated with a DMT. However, when analysing access to high efficacy DMT as a first drug, a strategy that has been focused in the updated national treatment strategies, we did not find that deprived pwMS had less access. Access to high efficacy treatment was determined by disease severity, independent of the SES. We concluded that since 2012, the pwMS in this Norwegian cohort are treated equally with DMT in terms of different measures of socioeconomic position.