Intestinal-type adenocarcinoma of the nasal cavities and paranasal sinuses is a relatively rare tumor. Standard therapeutic modalities include surgery followed by radiotherapy, sometimes with chemotherapy treatment. Despite these treatments, the outcome is poor due to frequent local recurrences constituting the main cause of death among patients; leptomeningeal carcinomatosis is not a frequent event, and its presence indicates short expected survival. The therapy of neoplastic meningitis includes cranial irradiation, intrathecal chemotherapy and high-dose systemic chemotherapy. However, these approaches report important side effects with only modest efficacy. Thus, it is important to discover better treatment for this cancer complication. We present, for the first time, a case of leptomeningeal carcinomatosis from invasive intestinal-type adenocarcinoma treated with temozolomide and cisplatin chemotherapy obtaining a prolonged reduction and stabilization of the lesion improving the clinical condition of the patient.