The Guidelines on Diagnosis, Treatment and Prevention of Venous Thrombosis (1) created by the Working Group on Angiology and Peripheral Vascular Diseases of the Croatian Cardiac Society is the document synthetized as personal experience but scientifically based on guidelines that were published by ACCP in 2012 and 2016 published in Chest, created by ESC Guidelines on Acute Pulmonary Embolism (2) from 2014 and according to the document of International Union of Angiology 2013. Croatian Cardiac Society as the member of ESC follows all the documents and guidelines published by European Society of Cardiology. Working Group on Angiology and Peripheral Vascular Diseases of the Croatian Cardiac Society faced the needs to offer professional paper on venous thrombosis and thromboembolism that could give the rational strategy and help to overcome diversity in diagnostic and treatment modality of Croatian health professionals for the best of Croatian patients with venous thrombosis. The guidelines will offer the structured pathway in diagnostic, therapeutic and preventive strategies according to specific patient population even before ESC professionals decided to do the same. Concepts in treatment and prevention of venous thrombosis were changed in the past years in most European countries with new drugs; novel anticoagulant drugs that offer greater safety and same efficacy in patients’ management. Those trends were recognized as the challenge to improve and change the therapeutic regime of venous thrombosis and thromboembolism the same as the treatment of acute pulmonary embolism. The guidelines are divided into the chapters starting from epidemiology, diagnostic and therapeutic modalities, the strategy and preventive measures in surgical and medical ill patients, in pregnancy, in cancer patients etc. We expect the professionals would be encouraged with the help of the guidelines, all those who deal with risk and treatment of venous thrombosis such as specialists in cardiology, internal medicine, anesthesiology, geriatric professionals, general practitioners and many other.