Introduction: Pulmonary thromboembolism occurs mostly as a complication of deep venous thrombosis. Pulmonary embolism is the third most common cause of cardiovascular death behind coronary artery disease and stroke. Studies with sialic acid have demonstrated that there is an association between serum total sialic acid levels and cardiovascular mortality and atherosclerosis. Also, there are studies that showed increased serum total sialic acid levels in ischemic conditions such as acute myocardial infarction. We aimed to investigate whether sialic acid could be used as a marker to support or exclude a diagnosis of pulmonary embolism like D-dimer.