Deep vein thrombosis (DVT) is a rare post transplant multifactorial disease and often results from a combination of risk factors causing venous stasis. Venography and doppler ultrasound are reliable and accurate procedures for detecting venous thrombosis. Once DVT has been established, these patients should be treated with anticoagulants at least for a limited duration particularly in high risk post transplant patients with previous episodes of thrombotic events. We report here a case of a 7 years old boy with B-thalassaemia major, who developed deep vein thrombosis at 04 month post SCT. He was treated with low molecular weight heparin and oral warfarin sodium and INR was stabilized between 2.5 - 3.0. Two months later, he presented with bleeding diathesis and died intracranial haemorrhage. Excessive unchecked anticoagulation was the cause of death. It is recommended that patients on anticoagulation therapy require strict monitoring with PT/INR to avoid bleeding complications related to unchecked over anticoagulation.