Carcinomatous meningitis is a rare neuropathological entity in the routine oncology practice, with an estimated frequency of one case in ten metastatic cancers (10% or less). Lung cancer, breast cancer, melanoma, or primary brain tumors usually have the propensity to generate meningeal metastases according to the literature. We herein report unusual cases of Carcinomatous meningitis diagnosed in two young patients of 46 and 38 years old who were primarily followed up for metastatic ovarian cancer and metastatic gastric cancer respectively. Neurological symptoms were prominent at the time of diagnosis. The brain scan was non-contributory. The radiological diagnosis was made by injected brain magnetic resonance imaging (MRI) which showed metastatic meningeal lesions in both cases. Anatomopathological analysis of the cerebrospinal fluid (CSF) was decisive in revealing cancerous cells. The treatment consisted of a doublet of intrathecally (IT) Methotrexate-Depomedrol (patient with ovarian cancer) and a triplet of IT Methotrexate-cytarabine-Depomedrol (patient with gastric cancer). The evolution was marked by a clinical improvement without CSF sterilisation for the patient on the doublet treatment but died 5 months later on the occasion of a new progression. For the other patient on the triplet, the evolution was towards a rapid clinical deterioration with death within 2 months from diagnosis. Carcinomatous meningitis is therefore a serious complication that rapidly threatens the life of patients. Survival rarely exceeds 4 months.