Leptomeningeal carcinomatosis is a neurological complication of several systemic tumors and is characterized by multifocal invasion of the meninges by neoplastic cells. It is estimated that 5% of all patients with cancer will present leptomeningeal carcinomatosis at some time during the course of the illness. Clinical manifestations are heterogeneous and present with signs and symptoms related to involvement of multiple areas of the nervous system, particularly cranial nerves and spinal roots. The diagnosis is based on suggestive clinical findings, cerebrospinal fluid (CSF) testing and imaging studies. The most informative findings come from CSF where the presence of neoplastic cells is definitive for the diagnosis. The purpose of this report is to describe, along with a review of the literature, a clinical case of a 42 years old man in whom the first clinical signs of a lung cancer manifested with symptoms suggestive of meningeal involvement.