Pulmonary embolism (PE) is according to the Guidelines on the diagnosis and management of acute pulmonary embolism a common cardiovascular emergency. By occluding the pulmonary arterial bed it may lead to acute life-threatening but potentially reversible right ventricular failure. PE is a difficult diagnosis that may be missed because of non-specific clinical presentation. PE is not a disease on its own rather it is a complication of other systemic hypercoagulability states; Such as deep vein thrombosis (DVT), pregnancy, smoking, cancer, hormone replacement therapy, contraception, genetic factors and many more. Due to this fact and due to the fact that it usually presents with nonspecific symptoms, PE diagnosis is sometimes very difficult. Acute PE is usually a consequence of primarily haemodynamic problems and can be seen in when as much as 30-50% of the pulmonary arterial bed is occluded by thrombus. Symptoms of PE are usually nonspecific and this makes the diagnosis of PE a hard one to make even in this day and age. The clinical presentation has a high importance in order to interpret the diagnostic test results and to plan the diagnostic strategies. In as much as 90 % of cases suspicion on PE is raised because of the presence of symptoms such as dyspnoea, chest pain and syncope, either singly or in combination. From all the symptoms pleuritic chest pain, whether or not combined with dyspnoea, is one of the most frequent presentations of PE. The levels of the D-dimer, compression ultrasonography and computed tomographic venography, as well as computed tomography which if it shows that a thrombus is shown up to the segmental level than it can be taken as good evidence for PE, are other diagnostic tools that can be used to diagnose DVT and PE, “Ventilation–perfusion scintigraphy is a robust and well-established diagnostic test for suspected PE. Pulmonary angiography is one of the more reliable diagnostic procedures of PE but its invasiveness limits its use to times when noninvasive tests don’t yield satisfactory results. We today have available tools to guide us and support our decision making; we have tools to classify the stability of our patients, and with diagnostic tools such as heart ultrasound, which is most important for patient suffering from high-risk PE, we can do bedside evaluation of the patient and appropriate treatment would be given to the patient on time. The availability of diagnostic tools as well as the availability of different treatment options will hopefully in the future give us the ability to even better understand this complication and treat the underlying cause of it.