Objective: The red blood cell distribution width (RDW) is a prognostic marker in patients with active or chronic inflammation, cardiovascular and the other autoimmune diseases. Our aim of this study is to evaluate levels of the RDW in patients with multiple sclerosis, disease subtypes and attacked groups. Material and Methods: Multiple sclerosis (MS) patients and healthy individuals were included in the study. Demographic characteristics of MS and control group, types of MS, MS attacks or no attack, and laboratory parameters analysis was evaluated. The RDW was calculated according to the formula: RDW = (Coefficient of Variability of RBC ÷ mean MCV) × 100. All groups and subgroups were compered according to RDW-value. Results: The study was conducted 105 MS patients, 74 (70.5%) females and 31 (29.5%) males, with a mean age of 38 (20-64) years. RDW values in the MS group were 13.8 (12.1-27.1), whereas in the control group the values were 13.4 (12.1-17.4) (p=0.007). ROC analysis revealed that using a cut-off point of 13.55, RDW predicts MS with a sensitivity of 59% and specificity of 54.2%. There was no statistically significant difference among the MS subgroups and attacked groups according to RDW value (p=0.41, p=0.92).