A case is reported of ruptured posterior communicating artery aneurysm presenting as a painful ophthalmoplegia syndrome (spheno-cavernous syndrome). This case suggests that there is need to carried out immediately neuroradiological studies when a painful ophthalmoplegia appears because of possible underlying intracranial aneurysm. This decisional algorithm should decrease the probability of aneurysmal rebleeding and increase the chance of oculomotor nerve function recovery.