Pulmonary thromboembolism can be a cardiovascular killer particularly during prolonged hospitalisations for surgical or medical illnesses. It is usually consequent to deep venous thrombo embolism but can also be due to hypercoaguable states. We report a rare case of acute Pulmonary Thromboembolism, diagnosed clinically and proven by CT pulmonary angiography in a 27 year old male with hyperhomocysteinemia, who was treated successfully with anticoagulants, folic acid and pyridoxine.