Leptomeningeal carcinomatosis (LC) is a rare and mainly secondary site of metastasis in solid tumors. In gastric cancer (GC), it is associated with a devastating prognosis, lacking an efficient and standardized treatment approach. We report a case of primary manifestation of LC due to metastatic GC with rapid deterioration and refractory course to conventional and intrathecal chemotherapy. We review the literature and discuss the therapeutic challenges.