The ductus arteriosus is a vascular structure of the foetal circulation that connects the great arteries and determines the blood flow from the pulmonary trunk to the aorta bypassing the pulmonary circulation. After birth, it comes to the functional and structural closure of the ductus arteriosus and the foetal circulation changes into circulation of adult type. Sometimes, however, physiological degradation of the duct after the first few weeks of life does not happen – this situation is called patent ductus arteriosus and accounts for approximately 10% of congenital heart defects. Patent ductus arteriosus may be asymptomatic or manifest itself with disturbances, mainly associated with the respiratory and circulatory systems, as well as disorders of other organs. A common clinical symptom is a characteristic continuous murmur, called machine-like murmur. The occurrence and severity of symptoms depend primarily on the size of the shunt through the duct and also on the age of the patient. The major complications of patent ductus arteriosus are bacterial endocarditis and pulmonary vascular disease. Treatment is based on the definitive closure of the ductus. During the first few weeks after birth, pharmacological closure with cyclooxygenase inhibitors (indomethacin, ibuprofen) is possible. Patent ductus arteriosus can also be managed with the use of non-invasive techniques (catheter procedures) or surgical treatment (a less invasive video-assisted thoracoscopy is also possible). The situation is different when there are complex anatomical heart defects in which the postnatally patent ductus arteriosus plays a different, beneficial role – these are so-called ductus-dependent defects. The management of such patients consists in maintaining the patency of the ductus arteriosus, because it determines the normal blood flow. There are also rare cases of premature (prenatal) closure of the ductus arteriosus, which may lead to the failure of foetal circulation.