Multiple sclerosis (MS) is a long lasting degenerative, often episodic disease of the central nervous system marked by patchy destruction of the myelin caused presumably by an autoimmune process [10]. More people are reportedly contracting MS [11]; the increase has been witnessed in Iran’s population as well [12]. A number of genetic variations are known to contribute to the risk of contracting MS. Some genes suspected to have been involved in MS initiation, e.g. MMP-9 [13] and TIMP-1 [14] have already been investigated in the Iranian population.  In addition, we studied association of several gene polymorphisms and expression involving in immune system with MS disease [15-19]. Nonetheless, there are many more genes, such as the IFNs, still waiting to be investigated. To this end, the current study aims to evaluate the expression of IFNAR1gene in whole blood of relapsing-remitting MS (RR-MS) patients, the most common form of MS, compared to normal individuals.