One of the latest studies in the genetics field is the evaluation of role of micro-RNAs as a biomarker for diagnosis of multiple sclerosis (MS), which is a demyelinating disease of the central nervous system (CNS) and emerges in the form of numerous small and large plaques in white matter in the brain and spinal cord. This disease could be associated with several complications, including reduced vision, spasticity and imbalance, and impaired sphincter control. MiR-202-3p is an intronic miRNA located in the ADA (Adenosine Deaminase) gene, which is the main enzyme involved in the pathway for the conversion of adenosine into inosine. Moreover, ADA regulates the inflammatory response and protection of tissue from damage as a strong complementary mechanism. This study aimed to evaluate the expression level of miR-202-3p in individuals diagnosed with relapsing-remitting multiple sclerosis (RRMS) and healthy individuals in Isfahan, Iran.