Isolated quadrilateral plate fractures are extremely rare and their treatment is complex. The postpartum period and recent caesarean section additionally increase already significant risks of surgical treatment. Modified Stoppa approach and the use of infrapectineal plate represent the optimal surgical treatment method. One case of central hip dislocation and isolated quadrilateral plate fracture was reported during an epileptic seizure 1 day postpartum, which was treated with open reduction and internal fixation. A 25-year-old female patient had given birth via cesarean section. One day postpartum, she had multiple generalized tonic clonic seizures. Arteriovenous malformation was identified as the cause of seizures by MRI. The patient complained of left hip pain and inability to move the left leg which prompted clinical and radiological examination. A pelvic CT scan verified multifragmentary fracture of the quadrilateral plate without fracture of the acetabular columns. The central hip dislocation was verified. Due to the rarity of the fracture, the clinical decision-making process was difficult. The patient, being in the post-partum period, was also at a greater risk of infection. The patient was treated surgically, and osteosynthesis was performed with an infrapectineal plate for the acetabulum using the modified Stoppa approach. The initial incision was done through the same Pfannenstiel incision from caesarean section. The patient's postoperative recovery was good at 1 year follow-up.