Duplication of the pituitary gland is a rare malformation. To the best of our knowledge, only 40 cases throughout the world have been reported previously. Due to associated severe developmental anomalies lots of these cases were diagnosed at autopsy. Only 7 patients survived beyond puberty, however, it is important to stress that none of them had major brain anomalies. We present the case of a girl with duplication of the pituitary gland (DPG), central precocious puberty and associated midline defects. Among fenestration of basilar artery, previously described in the literature, we also found, for the first time, a duplication of the M1-segment of the left median cerebral artery. Our patient is one of the 4 DPG patients with associated precocious puberty treated with gonadotropine releasing hormone agonists (GnRH), but the only one in whom this treatment was finished successfully.