Premature labour ranges from 6 to 8 per cents from all of the deliveries but it causes 75 80 per cents of the perinatal infant mortality. The purposes of the present research are: to prove the benefit of the tocolytic therapy in case of progressing premature labour (cervical dilatation 3 and more cm and distinguishable uterine contractions--at least 2 in 10 min for more that 1 hour); to compare the efficiency of the medicines used in tocolysis, as well as their influence on the maternal and infant morbidity and mortality; A successful tocolysis is considered to be the one, which delays the delivery for at least 48 hours. The authors concluded, that there is not any significant statistic difference in the tocolysis success with beta-adrenomymethics and the use aquatic solution of Magnesium sulfate. Better results were achieved in the cases when Indomethacin was added to the basic tocolytic medicine. No significant harms were observed in the maternal and infant organisms in result of the tocolytics application. It has been found that after the tocolytic therapy application the newborns were with greater birth body weight and the percentage of the respiratory distress was lower, compared to the group with expectant behaviour at hospitalization.