Objectives: To identify the high-risk factors associated with postpartum hemorrhage (PPH) after an elective cesarean delivery of twins. Material and methods: This retrospective cohort study included all women with twin gestations who chose to have an elective cesarean delivery after 28 weeks of gestation at at the Women’s Hospital, School of Medicine, Zhejiang University between September 2014 and April 2019. Women with an intrauterine fetal demise of one or both twins were excluded. PPH was defined as an estimated blood loss of ≥ 1,000 mL within 24 h of birth. A total of 532 women were analyzed and classified into the PPH group (n = 70) and the no-PPH group (n = 462). Univariate and multivariate logistic regression analyses were performed to assess the independent risk factors. Results: Among the 532 women pregnant with twins, PPH occurred in 13.2% women (n = 70). There were statistically significant differences in preeclampsia (p = 0.005), premature rupture of membrane (PROM, p < 0.001), placenta previa (p < 0.001), anemia [hemoglobin (Hb) < 100 g/L; p = 0.003], and antenatal magnesium sulfate (MgSO₄) use (p < 0.001) between the two groups. However, the following were the independent risk factors for PPH after an elective cesarean delivery for a twin pregnancy: preeclampsia [odds ratio (OR): 2.91; 95% confidence interval (CI): 1.33–6.36], PROM (OR: 8.57; 95% CI: 2.54–28.89), placenta previa (OR: 9.46; 95% CI: 3.59–24.89), antenatal MgSO₄ use (OR: 7.64; 95% CI; 3.18–18.41), and anemia (Hb < 100 g/L; OR: 2.68; 95% CI: 1.42–5.06). Conclusions: Preeclampsia, PROM, placenta previa,and antenatal MgSO₄ use were the risk factors for PPH after an elective cesarean delivery for twin pregnancies. Risk factor identification and prevention should be a priority.