Although the prevention of preterm birth remains the most important challenge in obstetrics, the mechanism for the onset of preterm labor has not been fully explained. The purpose of the present study is to investigate the usefulness of cervicovaginal fetal fibronectin and certain cytokines (interleukin-1B and interleukin-8) levels during pregnancy as markers of preterm and term delivery. This study was performed on 130 pregnant women at 24 to 29 years old age. The women were classified into group I (women not in labor, n=65) and group II (women with spontaneous labor, n=65). Each group was classified into two subgroups [preterm delivery (<37 weeks gestation, n=40) and full term delivery (>37 weeks gestation, n=25)]. We obtained cervicovaginal swabs for fetal fibronectin and cervicovaginal fluids for cytokines determination. The present study revealed that fetal fibronectin, IL- lB and IL-8 levels were significantly higher in patients in preterm labor than in patients at preterm not in labor. They were significantly higher in women at full term in labor than in women at full term not in labor. Interleukin- lB and IL-8 obtained from women not in labor increased exponentially as gestational age increased, and the cytokines levels were significantly correlated. This study revealed that cervicovaginal measurement of fetal fibronectin, IL-lB and IL-8 in combination with clinical findings may be useful for the evaluation of patients with threatened premature delivery.