Background and Objectives: Preoperative prophylactic balloon-assisted occlusion (PBAO) of the internal iliac arteries minimizes blood loss and facilitates surgery performance, through reductions in the rate of uterine perfusion, which allow for better control in hysterectomy performance, with decreased rates of bleeding and surgical complications. We aimed to investigate the maternal and fetal outcomes associated with PBAO use in women with placenta increta or percreta. Material and Methods: The records of 42 consecutive patients with a diagnosis of placenta increta or percreta were retrospectively reviewed. Of 42 patients, 17 patients (40.5%) with placenta increta or percreta underwent cesarean delivery after prophylactic balloon catheter placement in the bilateral internal iliac artery (balloon group). The blood loss volume, transfusion volume, postoperative hemoglobin changes, rates of hysterectomy and hospitalization, and infant Apgar score in this group were compared to those of 25 similar women who underwent cesarean delivery without balloon placement (surgical group). Results: The mean intraoperative blood loss volume in the balloon group (2319 ± 1191 mL, range 1000–4500 mL) was significantly lower than that in the surgical group (4435 ± 1376 mL, range 1500–10,500 mL) (p = 0.037). The mean blood unit volume transfused in the balloon group (2060 ± 1154 mL, range 1200–8000 mL) was significantly lower than that in the surgical group (3840 ± 1464 mL, range 1800–15,200 mL) (p = 0.043). There was no significant difference in the postoperative hemoglobin change, hysterectomy rates, length of hospitalization, or infant Apgar score between the groups. Conclusion: PBAO of the internal iliac artery prior to cesarean delivery in patients with placenta increta or percreta is a safe and minimally invasive technique that reduces the rate of intraoperative blood loss and transfusion requirements.