Thalidomide is an antiangiogenic drug, but its mechanism of action is not well known and demands further studies. The recent literature suggests that thalidomide is an effective drug in multiple myeloma patients. The objective of the study was to estimate the efficacy of thalidomide monotherapy in the treatment of refractory and relapsed cases of multiple myeloma. We treated with thalidomide 17 patients (12 males, 5 females), average age 51 (range 42-73 years), mean time since diagnosis to the start of thalidomide treatment was 24 months (range 5-48). All patients revealed the features of progressive disease. The mean number of prior chemotherapy schemes was 2. Three out of 17 patients received high dose chemotherapy followed by autologous stem cell transplantation. Thalidomide was administered as monotherapy at a dose of 200 mg (n = 8), 300 mg (n = 1) and 400 mg (n = 8). The mean time of drug intake was 3 months (1-12). The criteria of clinical response were decline of paraprotein at least 25%, 50% and 75% in comparison to value before the treatment. In 5 cases (33%) 25% reduction of paraprotein was observed, 1 patient achieved 50% decline. In the responder group a tendency to decrease marrow plasmocytosis, total serum protein, beta M-2 and LDH was noticed. The good tolerance of the drug, especially in lower doses, and lack of myelosuppression effect allows to expect, that the combination of thalidomide with other cytostatic drugs will improve the efficacy in patients with refractory or relapsed myeloma.