Background: Premature rupture of membranes (PROM) is the rupture of fetal membranes before labour. When it occurs before 37 weeks, it is termed preterm prelabour rupture of membranes (PPROM), which is associated with increased maternal and perinatal morbidity and mortality. The early identification of at-risk cases is crucial. The platelet–lymphocyte ratio (PLR) from routine blood counts has emerged as a low-cost inflammatory biomarker for obstetric conditions. This study evaluated the association between maternal PLR and PPROM and explored its predictive value. Methods: This cross-sectional analytical study was conducted at the Department of Obstetrics and Gynaecology, Dhaka Medical College Hospital, from June 2022 to May 2023. Sixty pregnant women between 28 and 36+6 weeks of gestation were included: 30 with PPROM (Group A) and 30 healthy controls (Group B). Complete blood counts were performed and the PLR was calculated as the ratio of the platelet to lymphocyte count. Data were analyzed using SPSS version 26.0. Results: The mean age did not differ significantly between the groups (27.57±5.14 vs. 28.33±5.02 years; p=0.56). The platelet count was significantly higher in the PPROM group (269.63±63.4 vs. 207.43±46.5 ×10³/mm³; p<0.001), whereas the lymphocyte counts were comparable (p>0.05). The mean PLR was significantly higher in PPROM cases than in those with intact membranes (123.15±27.73 vs. 104.48±26.09; p=0.009). Conclusion: Elevated maternal PLR is significantly associated with PPROM and may serve as a simple, cost-effective inflammatory marker for risk identification in pregnancies. Larger multicenter studies are needed to confirm its clinical utility.