A 6-year-old girl was admitted to our emergency room because of a gunshot wound in the posterior craniocervical junction. On admission, she was alert, but left hemiplegia and right hemiparesis were noted. Cranial CT scanning showed a retained bullet in the cerebellomedullary cistern without bone destruction. Moreover, fourth ventricle hemorrhage was observed. There were no signs of acute hydrocephalus. The patient underwent suboccipital craniectomy and C-1 laminectomy for bullet removal. Postoperatively, the patient experienced significant neurological improvement. To the best of the authors' knowledge, this is the first documented case of a patient with a retained bullet in the cerebellomedullary cistern. The management strategies in such a unique case are discussed.