Few data are available on the incidence of venous thromboembolism occurring in renal transplant recipients and optimal duration of oral anticoagulant therapy after thrombotic episode. Our study was performed to evaluate the risk of thrombosis recurrence in patients developing a first episode. Among 484 renal transplant patients 34 (7%) developed a first thromboembolism and were referred to the Thrombosis Centre: 28 patients (group 1) were prospectively studied, after stopping anticoagulants. Group 1 was compared with a group of 84 patients without an history of renal disease who had suffered from a first thrombotic episode and were matched for age, sex, and type of thrombotic event (group 2). During follow-up, 14/28 group 1 patients and 8/84 group 2 patients experienced thrombotic recurrence (P = .0001). Our data outline the high risk of recurrence in renal transplant recipients. Strategies for recurrence prevention are needed taking into account the high bleeding risk of anticoagulants in renal transplant patients.