Venous thromboembolism is a common complication in patients with cancer, but only limited data are available in acute myeloid leukemia (AML). In a prospective study in a cohort of 272 adult patients (aged 18-65) and an independent validation cohort of 132 elderly adults (aged >60) with newly diagnosed AML, we assessed markers of disseminated intravascular coagulation (DIC) (fibrinogen, D-dimer, α-2-antiplasmin, antitrombin, prothrombin time, and platelet count) and the DIC score according the International Society of Thrombosis and Haemostasis and their associations with the occurrence of venous and arterial thrombosis during follow-up. The prevalence of thrombosis was 8.7% (4.7% venous, 4.0% arterial) in the younger adults over a median follow-up of 478 days and 10.4% (4.4% venous, 5.9% arterial) in elderly patients. Most thrombotic events (66%) occurred before the start of the second course of chemotherapy. The calculated DIC score significantly predicted venous and arterial thrombosis with a hazard ratio (HR) for a high DIC score (≥5) of 4.79 (1.71-13.45). These results were confirmed in the validation cohort of elderly patients with AML (HR 11.08 3.23-38.06). Among all DIC parameters, D-dimer levels are most predictive for thrombosis with an HR of 12.3 (3.39-42.64) in the first cohort and an HR of 7.82 (1.95-31.38) in validation cohort for a D-dimer >4 mg/L vs ≤4 mg/L. It is concluded that venous and arterial thrombosis may develop in ∼10% of AML patients treated with intensive chemotherapy, which to a large extent can be predicted by the presence of DIC at time of AML diagnosis. •A high D-dimer level strongly predicts symptomatic venous and arterial thrombosis in newly diagnosed AML.•Thrombosis occurs in up to 10% of patients with newly diagnosed AML.