Symptomatic interhemispheric arachnoid cysts (ACs) are extremely rare lesions seen more frequently in the elderly. Only 13 cases of symptomatic interhemispheric ACs in the elderly have previously been reported. Herein, we describe a 70-year-old female with symptoms of vertigo, memory and behavior disturbances. Magnetic resonance imaging (MRI) revealed a giant arachnoid cyst (AC) on the interhemispheric fissure, which was exerting a mass effect and displacement on the corpus callosum and anterior cerebral vessels, with a massive midline shift. The patient was treated with a cysto-peritoneal shunt. Reports to date have reviewed the pathology, clinical presentation, radiology and surgical management of interhemispheric symptomatic arachnoid cysts in elderly patients.