Two uncommon cases of unilateral, asymmetrical hydrocephalus secondary to membranous occlusion of foramen of monro are described. Both the cases presented with clinical features of raised intracranial pressure and their cranial computerized scans (CT) revealed asymmetrical dilatation of lateral ventricles with displacement of septum pellucidum towards the side of smaller ventricle. Neuroendoscopic fenestration of septum pellucidum and foramen of monro was tried in both the cases, which remained successful in first, while the second case required unilateral ventriculoperitoneal shunt, due to failed endoscopic negotiation of narrowed foramen of monro and intraoperative bleeding during endoscopic intervention.