Pulmonary Embolism (PE) implies clinically significant obstruction of a part or whole of the pulmonary artery tree usually by a thrombus. In most cases, PE is a consequence of deep vein thrombosis of the lower extremities or pelvis. PE is a well recognized potentially life threatening disease if left untreated. This is due to recurrence and the possibility of acute and often fatal right ventricular failure. The predisposing factors as suggested in Virchow’s triad include immobilization, post operative period, trauma, pregnancy and puerperium. Clinical features are non specific and include dyspnoea, haemoptysis, pleuritic chest pain and wheezing. There are two types of presentation acute and chronic. Prompt evaluation through is required to initiate appropriate treatment. In the acute setting computed tomogram pulmonary angiogram has become the mainstay, although ventilation perfusion scan and echocardiogram could also help to make diagnosis. The gold standard remains pulmonary angiogram. Prevention of development of thrombus (prophylaxis), clot propagation and recurrence (anticoagulation) along with direct treatment in unstable patients (thrombolysis) remain the main principles of treatment. Vena caval filters can prevent propagation in large free floating thrombus. Surgical pulmonary endarterectomy can provide patients with definitive cure in the chronic variety. Improved imaging techniques have resulted in early diagnosis and exceedingly few patients develop cor pulmonale.