Leptomeningeal involvement is usually reported as a secondary event in advanced gastric carcinoma. Leptomeningeal carcinomatosis (LMC), as the initial manifestation of asymptomatic gastric cancer, is exceedingly rare with only a few cases reported in recent years. The presenting neurologic symptoms include headache, vomiting and seizures and are usually clinically atypical. The diagnosis of LMC is made via identification of malignant cells that originate from epithelial cells in the cerebrospinal fluid by cytological examination and provides cues to track the primary tumor. Endoscopic examinations are crucial to confirm the presence of gastric cancer, and imaging studies, especially gadolinium-enhanced magnetic resonance imaging of the brain, are sometimes helpful in diagnosis. Thus far, there is no standard therapy for LMC, and despite all measures, the prognosis of the condition is extremely poor. Here, we report on the clinical features and diagnostic procedures for a patient with occult gastric cancer with Bormann type I macroscopic appearance and poor differentiation in pathology, who presented with LMC-induced neurological symptoms as the initial clinical manifestation. Additionally, we review the similar cases reported over the past years, making comparison among cases in order to provide more information for the future diagnosis.