Postpartum peripheral nerve disorders are an uncommon obstetrical complication, with most cases resulting from intrinsic obstetric palsies. We present the case of a full-term nulliparous pregnant 33-year-old woman with a vacuum-assisted vaginal delivery due to a prolonged second stage of labour and occipitoposterior position of the fetal head. For analgesia, a combined spinal-epidural technique was used. Four hours after delivery, the patient experienced a painless asymmetric motor deficit and hypoesthesia in the lower limbs, followed by sphincter disturbance. Emergent MRI was unremarkable. Electromyography showed signs of a bilateral lumbosacral radiculopathy. The patient experienced a gradual recovery over the following 2 months. Although a definitive aetiological diagnosis could not be confirmed, a lumbosacral polyradiculopathy due to intrinsic obstetric complication was considered. The patient presented several risk factors known to be associated with intrinsic obstetric palsies. Obstetricians and anaesthesiologists have an important role in preventing and diagnosing postpartum peripheral nerve disorders.