A ruptured aneurysm arising from the total duplication of the posterior communicating artery

•The authors report a ruptured aneurysm arising from the total duplication of the posterior communicating artery (PcomA) and the ophthalmic artery originated from cavernous portion anomalously.•An aneurysm arising from the duplication of the PcomA is extremely rare.•The PcomA duplication-in addition to the ophthalmic artery’s anomalous origin-was speculated to be an anomaly related to the developmental processes of cerebral arteries.