Multiple sclerosis (MS) is an autoimmune disease whose features include a massive lymphocyte recruitment into the central nervous system and segmental demyelinization of the white matter. One of the MS development factors is an increase of matrix metalloproteinases (MMPs) activity with a coincidental decrease of tissue inhibitors of MMPs (TIMPs) activity. Investigations of serum, cerebrospinal fluid and brain tissue of patients showed an increase of MMP-1, -2, -3, -7, -9 and MMP-12 activity. MMPs disrupt the blood-brain barrier (BBB), increase lymphocyte migration into the central nervous system and are involved in degradation of myelin proteins. MMPs induce the appearance of an active form of tumor necrosis factor alpha, a strong proinflammatory cytokine. The drugs used in MS treatment decrease MMPs expression. Multiple actions of MMPs prove their involvement in the pathogenesis and treatment of MS.