Summary and Conclusion• Preterm birth remains a major cause of perinatal morbidity and mortality, and probably the most challenging problem in modern obstetrics.• Accurate prediction of preterm labor reduce hospitalization and unnecessary medications that drain the resources, and allow choosing the proper time for the selected intervention.• Recently the question has been raised of whether a high serum ferritin concentration is of value as a marker of impending preterm delivery. It has been hypothesized that high third trimester concentration correlates with very preterm delivery caused by subclinical maternal infection (Tamura et al, 1996)• Normally serum level lies within the range between 15-300 ng/ml but these concentrations are dependant on both age and sex, the level drops markedly in pregnancy because of feto-placental demand and the required expansion of the red cell mass.• To determine the role of maternal serum ferritin concentration in cases of spontaneous preterm delivery (as a predictive marker of preterm labor) and to compare its concentration at deferent grades of preterm labor, this study was performed.The patients are classified into two groupsFirst group included 48 patients with gestational age between (24-32) weeks of pregnancy, subdivided into:-(A) 32 patients with spontaneous preterm delivery with gestational age between 24 : 32 weeks of pregnancy (study group).(B) 16 pregnant women with no spontaneous preterm delivery with gestational age between 24 :32 weeks of pregnancy (control group).second group included 48 patients with gestational age between (33-37) weeks of pregnancy, subdivided into:-(A) 32 patients with spontaneous preterm delivery with gestational age between 33 : 37 weeks of pregnancy (study group).(B) 16 pregnant women with no spontaneous preterm delivery with gestational age between 33:37 weeks of pregnancy (control group).*Control groups included normal pregnant women who had antenatal care and followed up until full term delivery.• Serum ferritin was estimated for all cases and control subjects by Enzyme Linked Immuno-Sorbent Assay (ELISA) method.• The results were statistically analyzed and show that serum ferritin concentration is statistically higher in all cases of spontaneous preterm delivery than control groups both in cases with gestational age between (24-32) weeks of gestations and cases with gestational age between (33-37) weeks of pregnancy.• Also the results show that increased serum ferritin in both study and control groups in gestational age between (24-32) weeks of gestations than both study and control groups in gestational age between (33-37) weeks of pregnancy.• So serum ferritin may be a useful addition to the current available parameters of antenatal care as a good marker of preterm labor specially for women at risk of preterm labor.• Serum ferritin not studied (in this study) in cases preterm labor with preeclampsia, DM, polyhydramnios, antepartum hemorrhage, …….etc to have a prediction role in diagnosis of preterm labor but of great importance in prediction and diagnosis of cases with spontaneous preterm delivery or cases with PROM (sub-clinical infections that lead to PROM and preterm labor).