Multiple sclerosis (MS) and systemic lupus erythematous (SLE) are autoimmune diseases, the coexistence of which is uncommon in patients. Owing to the rarity of this condition, the distinction between MS and SLE is a diagnostic challenge for neurologists. We present a case report in which MS and SLE were present in the same patient. There are few case reports in the world on the association between MS and SLE. The following case report is the first of its kind in which both MS and SLE are present in a patient from a country with low prevalence of MS such as Ecuador.