Background: Leptomeningeal Carcinomatosis (LMC) is defined as a diffuse or multifocal malignant infiltration of the Pia matter and arachnoid membrane. It is clinically diagnosed in 5-10% of all cancer patients. The most commonly reported cancers associated with LMC are breast, lung and hematological malignancies. Patients with LMC commonly present with multifocal neurological symptoms. Symptoms are related to increase intracranial pressure, hemispheric dysfunction, cranial neuropathies and spinal roots dysfunction. We report a case of LMC secondary to Gastroesophageal junction cancer present initially with Cauda equine syndrome. Methods: A 51 year old male patient with adenocarcinoma of Gastroesophageal junction who underwent surgical resection, chemotherapy and radiation therapy. Nine month after diagnosis he presented with left leg pain, mild weakness and saddle area numbness. Initial radiological examination were unremarkable. Subsequently he had worsening of his leg weakness, fecal incontinence and urine retention. Two days later he developed rapidly progressive cranial neuropathies including facial diplegia, sensorineural hearing loss, dysarthria and dysphagia. Results: MRI with and without contrast showed diffuse enhancement of leptomeninges surrounding the brain, spinal cord and Cauda equine extending to the nerve roots. Cerebrospinal fluid cytology was positive for malignant cells. Conclusion: In cancer patient with Cauda equina syndrome and absence of structural lesion on imaging, LMC should be considered.