Background/Aim. Prediction and prevention of preterm delivery remain great challenge. It is important to include in everyday medical practice determination of certain markers that could help identifying pregnant women with preterm delivery. Insulin like growth factor (IGF) is involved in the control mechanism of fetal and placental growth and development. The aim of this study was to examine the presence of insulin-like growth factor binding protein 1 (IGFBP-1) in cervicovaginal secretion of pregnant women with symptoms of preterm labor, but with apparently intact fetal membranes and to point out a possible application of the strip test for detection of phIGFBP-1 in diagnosis of preterm premature rupture of total membranes (PPROM) in everyday medical practice. Methods. The study was performed at the Department for Obstetrics and Gynecology, Clinical Center of Vojvodina between October 2008 and May 2009. The study included 54 pregnant women between 20-35 weeks of gestation (WG), divided into two groups: the study group (16 pregnant women with symptoms of preterm delivery that gave birth before 37 WG) and the control group (38 pregnant women with the normal course of pregnancy that gave birth on term). In cervicovaginal secretion of the examined pregnant women the level of IGFBP-1 was determined by the immunochromatographic assay with monoclonal antibodies 6303 as a detecting antibody (Actim PROM test, Medix Biochemica, Kauniainen, Finland). Results. Gestational age (GA) at delivery in the study group was 32.6 WG and in the control group it was 38.4 WG. Weight of newborns in the study group was 2,021 g and in the control group 3,430 g. IGFBP test was positive in 15 women (93.75%) of the study group, while in the control group it was positive only in 1 woman (2.63%). Conclusion. Test on phIGFBP-1 in cervicovaginal mucus was positive in 93.75% women with preterm delivery, suggesting that this test could be used in diagnosis of silent rupture of fetal membranes and in prediction of preterm delivery.