Background Preterm birth (PB), defined as birth occurring at less than 37 weeks of gestation, is a leading cause of perinatal mortality and morbidity in the world. Objectives This study aimed to evaluate the socio-demographic characteristics and etiological factors associated with preterm birth and consequent adverse perinatal outcomes retrospectively at a tertiary care hospital. Methods A single-centre retrospective observational study was conducted in the department of Obstetrics & Gynaecology, Fakir Mohan Medical College & Hospital, Balasore, Odisha, India, from April 2019 to March 2020. Data were retrieved from the antenatal ward admission register, case files, theatre records, and neonatal care unit records and reviewed. Descriptive statistics were used to describe data. Chi-square test and student’s t-test were used to find significance of difference between variables. Results The incidence of preterm birth in the study population was 5.52%. The mean gestational age of preterm deliveries was 34.39 ± 1.92 weeks. The bulk of the women hailed from a rural background and belonged to the lower socioeconomic strata. About 47.29% of the women were nulliparous and spontaneous preterm birth was noted in 70.40%. Premature rupture of membranes (PROM), anaemia, intrauterine growth restriction (IUGR), preeclampsia, and eclampsia were the most common adverse pregnancy conditions prevalent in these women. Preterm deliveries comprised 31.21% of all neonatal intensive care unit (NICU) admissions. Respiratory distress syndrome, birth asphyxia, neonatal sepsis, and jaundice were the most common complications. Neonatal death occurred in 51 (9.21%) preterm infants with birth asphyxia being the commonest cause of such deaths. Maternal factors and adverse neonatal outcome variables were compared between the spontaneous and iatrogenic/medically indicated preterm birth groups. Preeclampsia, IUGR, and cesarean section were more significantly associated with the iatrogenic group. Conclusion Our study provides a general overview of the associated etiological factors and perinatal health concerns associated with preterm birth in a rural/semi-urban setting in Eastern India. The findings might provide essential data for taking steps toward the prevention and management of preterm birth from a developing country’s perspective.