摘要:Purpose: Adherence to disease-modifying treatments is essential in order to maximize the beneficial effects of treatment for multiple sclerosis (MS). There are numerous treatments that have been approved. Treatment selection is essential in patient adherence. In addition, patient preference plays an increasingly significant role in treatment decision-making. This study aims to evaluate the degree of adherence, along with other variables that may influence this adherence, in Spain. Methods: A cross-sectional study was conducted with 157 MS patients with disease-modifying treatments. Adherence was assessed using the Morisky Green scale, and other related factors were measured using a questionnaire that addressed demographics, disease characteristics, global perception of pathology, impact of medication on patient’s life, and treatment decision-making. Results: The adherence rate was 71% and was associated with the following variables: older age, more treatments received, time to diagnosis 5–10 years, absence of exacerbations, better cognitive status, being married/in a union, clear information about the disease, and higher treatment satisfaction. The main cause for non-compliance was forgetfulness (27%). Conclusion: The adherence rate is acceptable. It is widely known that treatment satisfaction is related to adherence. In our study, patients’ level of satisfaction was higher with oral treatments. However, oral administration showed a greater lack of adherence. The main cause of lack of adherence was forgetfulness. In relation to other variables, cognitive status and family support showed a correlation with treatment adherence.