Leptomeningeal carcinomatosis (LMC) is exceedingly rare in gastric cancer. It is most commonly seen in breast, lung cancer and melanoma, and is associated with an extremely poor prognosis. If untreated, median overall survival is four to six weeks. No standard treatment for LMC exists and published data are scarce. We present two cases of gastric carcinoma diagnosed with LMC that exemplify how aggressive this condition is and how short the time lapse is to perform any targeted therapy. This report aims to raise awareness of this rare metastatic possibility in gastric cancer and its diagnostic and therapeutic challenges.