The risk of venous thromboembolism (VTE) in patients with cancer is several-fold higher than that in individuals without cancer. Recent studies demonstrated a high incidence of VTE in patients with hematologic malignancies as well as in patients with solid cancers. The reported incidence of VTE in lymphoma is variable, ranging from less than 5% to 59.5%. The incidence of VTE is higher in non-Hodgkin lymphoma than it is in Hodgkin lymphoma. The incidence of VTE also varies according to the disease grade, the disease stage, the performance status of the patient, and the site of disease. Most VTE cases occur at the diagnosis of cancer or early in the course of cancer treatment. An elevated incidence of VTE is also reported in cases of myeloma. VTE occurs in approximately 5% of myeloma patients treated with conventional chemotherapy, and treatment of myeloma patients with immunomodulatory drugs (IMid)-based therapy increases the risk of VTE. Prophylactic aspirin or anticoagulant is used in myeloma patients treated with IMid-based therapy. Several reports have indicated that the incidence of VTE is relatively low in Asian patients treated with IMid-based therapy, and concomitant use of bortezomib reduces the risk of VTE. The incidence of arterial thrombosis is also increased in patients with myeloma and monoclonal gammopathy of undetermined significance. Further studies are needed to develop a predictive model for identifying patients with lymphoma and myeloma who are at high risk for developing thrombosis.