Venous thromboembolism (VTE) with its two clinical manifestations deep vein thrombosis (DVT) and pulmonary embolism (PE) is a life-threatening disease that is associated with considerable morbidity and mortality. The incidence of VTE increases with age and it - as the third most common cardiovascular disease after ischemic heart disease and stroke - represents an important public health problem in industrialized countries with several aspects in need to be addressed. VTEval Project includes three long-term prospective observational studies to evaluate and improve VTE diagnostics and management, treatment and outcome. The aims of the project include a systematic assessment of VTE, i.e. disease status (symptoms, clinical and subclinical aspects) and risk profiles (classic, psychosocial and environmental factors), using a system-oriented approach. VTEval collects three large prospective cohorts of patients with suspected and incident VTE consisting of individuals with a clinical suspicion of acute PE, individuals with a clinical suspicion of acute DVT, and individuals with incidental diagnosis of VTE). The standardized and harmonized data acquisition of the study establishes a sustainable resource for comprehensive research on VTE, thus providing the basis for both short- and long-term analysis.