Leptomeningeal metastasis(LM) usually occurs in patients with previous cancer. But rarely it can be the first manifestation of cancer. We analyzed primary tumors and early clinical findings in 12 patients in whom LM was the presenting sign of cancer. Primary tumors were lung cancer in 5 cases, stomach cancer 1, lymphoma 1 and unknown 5. Most patients, previously healthy, developed progressive headache which was followed by symptoms and signs involving multiple neuraxis. Major symptoms on admission were headache, nausea, vomitting, visual dimmness, diplopia, hearing disturbance and the major neurologic deficits were papilledema, ocular motor palsy, decreased DTR and neck stiffness. From these clinical findings and CSF test, initially LM was suspected in only 6 patients. In the remaining 6 patients, initial diagnosis were tuberculosis meningitis(3), benigh intracranial hypertension(2) and adjustment disorder(1). In addition to cytology, which was positive in 9 cases, CSF carcinoembryonic antigen(CEA) and neuroimaging played an important role in the early diagnosis of LM. Despite whole brain radiation therapy, all patients worsened and expired 2 weeks-10weeks(median survival, 3 weeks) after the diagnosis.