BACKGROUND: Congenital thrombotic risk factors, oncological diseases and its therapies have been related to an increased occurrence of upper extremities deep venous thrombosis (UEDVT). PATIENTS AND METHODS: We studied seven patients bearing lymphoma (one Hodgkin's and six non-Hodgkin's) who developed UEDVT, one at diagnosis and six during chemotherapy (two of these six cases had implantation of a central venous catheter and four received Growth Colony Stimulating Factors in addition to chemotherapy). Patients were screened for: factor V G1691A (Leiden), prothrombin G20210A, methylene tetrahydrofolate reductase (MTHFR) C677T mutations and antithrombin III, proteins C and S plasma activity. RESULTS: All patients were wild-type homozygotes for G20210A. One was heterozygote for factor V G1691A, the other 6 were wild-type homozygotes. Three of the 7 patients were homozygotes and 2 heterozygotes for the MTHFR mutation; the remaining 2 were wild-type homozygotes. Clotting inhibitor levels were normal in all patients. CONCLUSIONS: UEDVT in patients bearing haematological malignancies can occur irrespective of congenital thrombophilic alterations. However, in a subgroup of patients UEDVT could also depend on congenital thrombophilic alterations. A screening for inherited thrombophilia can identify high risk patients that could be specifically treated to prevent thrombotic complications.