MS is the most common neurological disease among young adults. The cause is elusive, although autoimmune mechanisms, possibly triggered by environmental factors in genetically susceptible individuals, are thought to be important. Occurrence of brain damage is frequently associated with abnormal blood-brain barrier (BBB) function. Two brain-specific proteins, S100B and neuron-specific enolase (NSE) are released systemically in a variety of neurological diseases. Serum levels of S100B and NSE are influenced by the dynamics of MS and they might differentiate between RR-MS (in remission and relapse) and SP-MS. A significant increase in the serum S100B levels of all patients groups versus the control group was found and it was positively correlated with serum NSE in MS patients. A significant increase in the serum NSE levels of patients in relapse and secondary progressive patients versus the control group was found and it was positively correlated with the EDSS score. S100B as a biomarker of astroglial activity may have a potential to distinguish patients in relapse from other forms of MS and On the other hand, NSE may have a potential as a marker of the degree of disability and / or outcome of the disease.