Objective — to evaluate the efficiency of using a synthetic oxytocin antagonist in threatened and incipient preterm labor. Subject and methods. The efficacy of the oxytocin receptor antagonist atosiban used during labor at 24—33 weeks 6 days’ gestation was analyzed in 176 patients. Group 1 included 92 pregnant women with clinical manifestations of threatened preterm labor; Group 2 consisted of 84 patients with clinical manifestations of incipient preterm labor. All the patients underwent ultrasonography with cervicometry, Doppler ultrasound, and cardiotocography. Tocolytic therapy with the oxytocin antagonist was performed in accordance with its clinical practice guidelines; its duration did not exceed 48 hours; the maximum cycle dose of the drug was 330 mg. The scales for evaluation of the fetal cardiovascular system and for subjective assessment of a pregnant woman’s health were used during the first 3, 24 and 48 hours of treatment. Lactation was quantitatively and qualitatively assessed on days 4—5 postpartum. Results. The oxytocin receptor antagonist atosiban was established to contribute to complete cessation of myometrial contractile activity in threatened preterm labor, to pregnancy prolongation by 48 hours in 57.1% of patients with incipient preterm labor, and to a full-term period in 38.1%. There was evidence for the higher efficacy of the drug in treating threatened preterm labor. Conclusion. The results of the study indicate that it is advisable to use the synthetic oxytocin antagonist of atosiban in threatened and incipient preterm labor.