**1. Introduction**

Acute Pulmonary embolism (PE) is an emergency. It needs immediate clinical evaluation for appropriate recognition due to the availability of appropriate therapeutic interventions to decrease its immediate mortality and avoid postthrombotic complications. Clinical manifestations of a patient coupled with the risk factors at initial presentation should guide to PE suspicion. In cases where the clinical scenario is not straightforward, multiple algorithmic score models should promptly guide the physician to diagnose PE. PE diagnosis is accomplished with the help of multiple imaging studies, of which chest computed tomography (CT) is the one used frequently. In this topic, we will glean over all the factors that help in diagnosing an acute PE.
