Background: Preterm birth is a major contributor to perinatal morbidity and mortality, with substantial immediate and long-term consequences for newborns. The present study was undertaken to assess the association between multiple pregnancy and preterm birth and to compare gestational age at delivery between singleton and multiple pregnancies among women attending a tertiary-care hospital in Bangladesh. Methods: This hospital-based observational study was conducted at the Department of Obstetrics and Gynaecology, Dhaka Medical College Hospital, Dhaka, Bangladesh, from January to June 2019 among 60 pregnant women. Sociodemographic and pregnancy-related data were collected, and preterm birth was defined as delivery before 37 completed weeks. Data were analyzed using frequencies, percentages, and the chi-square test, with p<0.05 considered statistically significant. Results: Among 60 participants, most were aged 21–25 years (35.0%), urban residents (56.7%), had secondary education (41.7%), and were multigravida (55.0%). Singleton pregnancies comprised 75.0%, while multiple pregnancies comprised 25.0%. Overall, 41.7% delivered preterm, predominantly at 32–36 weeks (28.3%). Preterm birth was significantly higher in multiple than singleton pregnancies (80.0% vs. 28.9%, p<0.001), with multiple pregnancies showing a greater concentration of deliveries before 37 weeks. Conclusion: Multiple pregnancy was significantly associated with an increased risk of preterm birth and earlier gestational age at delivery.