Background: Preterm labor, which is defined as giving birth before 37 weeks of gestation, is a significant global complication of pregnancies including both singletons and multiple fetuses. Premature babies have a higher chance of dying. Aim of study: Investigate the relationship between pregnancy-associated plasma protein-A (PAPP-A) levels and preterm birth in women who report experiencing premature labor. Methodology: It was a prospective case control study carried out from the 1st of January 2018 to the 20th of March 2019 at Basra maternity and children hospital. A total of 150 patients (50 patient with preterm labour (28-37 weeks), 50 patients with threatened preterm labour and 50 patient’s term pregnancy in labor) primary end point was delivery ˂37 weeks. All studied 3 groups were checked for serum maternal PAPP-A level on admission. Results and Discussion: In all 50 patients delivered before 37 weeks (Group I), 50 patients had symptoms of preterm labour but didn’t deliver preterm (Group II) and 50 patients (Group III) delivered at term, mean PAPP-A level in preterm group and its matched control group were 32.56±17.2 miu/ml and 53.21±18.42 miu/ml respectively and the difference was statistically significant (p-value 0.002), mean PAPP-A level TPL was 45.06±15.42 miu/ml and the difference was significant in compare to preterm labour but not significant in compare control group p-value 0.003 and p=0.74 respectively. Conclusion: PAPP-A level reduction in preterm labor was linked to an increased risk of preterm birth; a value of ˂ 33.6 miu/ml indicates a higher likelihood of a term delivery.