Progress in basic science as well as the dynamic development of medical equipment contributed substantially to the knowledge and understanding of the pathogenesis of preterm labour, which, together with the improvement of neonatal care, contribute to the reduction of infant mortality. Paper discusses the common causes of premature birth, and shows the possibilities of modern ultrasound in the diagnosis and its impact on further proceedings in these cases. Among the most common causes of premature birth include: obstetric infections of urogenital system, autoimmune diseases, cervical incompetence, congenital uterine abnormalities, fibroids, multiple pregnancy, polyhydramnios, oligohydramnios, fetal defects, pregnancy induced hypertension and eclampsia, abnormal location of the placenta, premature rupture of membranes. Modern ultrasound techniques are extremely important both in the emergence of high‑risk groups and the selection of appropriate treatment and monitoring its effectiveness. These studies include ultrasound of uterus, uterine cavity and cervix 2D and 3D presentation as well as elastography. Furthermore, assessment of uteroplacental‑fetal perfusion can select a high risk of developing pregnancy‑induced hypertension, fetal hypotrophy and the early detection of intrauterine hypoxia. In many cases it allows appropriate treatment as well as carefully and safely monitor the further course of pregnancy, and in due time decide to complete the pregnancy. Authors believe that the prevention of preterm birth should be a multistage, and ultrasonography together with the identification of patients at increased risk is an extremely important part of secondary prevention.