OBJECTIVE Peduncular hallucinosis is a rare phenomenon characterized by visual hallucinosis and agitation. It appears mainly in vascular lesions affecting the brainstem, and some recent reports describe the preoperative and postoperative appearance of peduncular hallucinosis in patients affected through tumor compression at the brainstem. METHODS Detailing the neurosurgical experiences with this syndrome, we review the available literature and provide pathoneurobiological insights to give the neurosurgeon an overall view of this phenomenon. RESULTS Peduncular hallucinosis resolves spontaneously, and supportive medications might be helpful. Sacrifice of brainstem draining veins during surgery might contribute to the symptoms. CONCLUSION The cranial base neurosurgeon should be aware not only of the phenomenon but the surgical influence in provoking it.