Deep venous thrombosis (DVT) has been variably reported in multiple myeloma patients during treatment with thalidomide alone or in combination with chemotherapy or dexamethasone. With the aim of investigating this complication, we performed, on a cohort of 13 relapsed refractory MM patients treated with low-dose thalidomide (100 mg/day) and dexamethasone (20 mg p.o./day for 4 days every 2 weeks), a serial evaluation of different laboratory parameters implicated in DVT. No significant abnormalities in all genetic, serologic, or plasmatic parameters studied were registered, apart from thrombomodulin which showed significant variations between baseline and 1st-month values and 1st- and 3rd-month values. In conclusion, the evidence of significant variations of thrombomodulin values in the 1st month of therapy, which is considered to involve the highest risk of thrombosis, might support a role for thrombomodulin in this complex mechanism.