Background: Environmental pollutants might be among the etiological factors for multiple sclerosis. The high rise of CD8 and CD4 is the commonly accepted pathway for the chronic inflammation of myelin sheath proteins developing the different clinical types of MS. Objectives: To measure the level of blood lead, cadmium, mercury, CD4 and CD8 among the different clinical types of MS cases compared to controls, to find out if there is a correlation between the level of the measured heavy metals and the degree of disability among the studied cases of multiple sclerosis.