The objective of the present study was to elucidate the influence of magnesium-containing preparations on the concentration of matrix metalloproteinases (MMP-1 and MMP-2) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in the patients presenting with primary varicose veins (PVV) in the lower extremities. Material and methods. The study included 124 patients presenting with class C2—C6 primary varicose veins divided into four groups. Group 1 was comprised of the patients (n=32) who received the surgical treatment followed by standard conservative therapy. The treatment of the patients of group 2 (n=32) received the surgical treatment with subsequent standard conservative therapy supplemented by magnesium-based preparations. Group 3 consisted of the patients (n=30) treated by conservative therapy in the absence of surgery. Group 4 was composed of the patients (n=30) given the standard conservative treatment and magnesium preparations. The surgical treatment consisted of crossectomy and stripping with subsequent miniphlebectomy and dissection of the perforating veins. The conservative treatment that lasted during 3 months included compression and phlebotrophic therapy. The patients of groups 2 and 4 were given magnesium orotate at a dose of 500 mg (3 tablets) thrice daily during 3 months. The levels of MMP-1, MMP-2, and TIMP-1 in the blood were measured with the use of the quantitative solid phase enzyme immunoassay. The concentration of the magnesium ions was determined by the colorimetric method. Results. The number of patients suffering from magnesium deficiency decreased in groups 2 and 4. The use of a magnesium containing medication resulted in a significant (р<0.05) reduction of the MMP-9 activity and of the activity of TIMP-1. The concentration of MMP-1 decreased under the influence of the treatment in the patients of all groups within 1 and 3 months after its initiation. Conclusion. The patients presenting with primary varicose veins in the lower extremities experience the reduction of the matrix metalloproteinase level under the influence of therapy. The use of the magnesium-containing preparations resulted in the decrease of the activity of matrix metalloproteinases-1 and -9 as well as of the activity of the tissue inhibitor of metalloproteinase-1 in the patients presenting with primary varicose veins in the lower extremities.