Objective: The authors aimed to determine whether concentrations of IL-6 and procalcitonin in maternal circulation can be used and compared with cervical length to predict the admission-to-delivery interval in preterm labour. Materials and Methods: Forty patients complicated with preterm labour between 24-34 weeks of gestation and having preterm birth were included in the study group. Fortyfour healthy pregnant women at similar gestational ages and having term labour (≥ 37 weeks) were included in control group. Maternal concentrations of IL-6 was measured by an enzyme-linked immunosorbent assay (ELISA) and procalcitonin was measured by immunoturbidimetry with using human procalcitonin reagent kit. Transvaginal ultrasound to assess cervical length was performed. Results: Receiver operator characteristic (ROC) analysis results of IL-6 and procalcitonin for prediction of preterm delivery (PTD) < 48 hours, < seven days, < 32 weeks, < 34 weeks, and < 37 weeks were not statistically significant (p > 0.05). ). It was shown through ROC analysis, that only cervical length had area under curve (AUC) 0.692 (0.511–0.873, p = 0.044) at cut off value ≤ 3.64 cm, AUC 0.758 (0.574–0.943, p = 0.015) at cut off value ≤ 3.50 cm, AUC 0.716 (0.553–0.879, p = 0.032) at cut off value < 3.80 cm, in predicting PTD within seven days, < 32 weeks and < 37 week, respectively. Conclusion: This study suggests that in preterm labour, although IL-6 and procalcitonin have unsatisfactory predictive value for the admission-to-delivery interval, cervical length has better predictive values for the admission-to-delivery interval.