Gliomatosis Cerebri (GC) is defined as a diffuse infiltration of a glial tumor generally astrocytic that involves at least 3 cerebral lobes bilaterally and usually the condition extends to the brainstem.Its incidence represents approximately 1% of all brain tumors and occurs more frequently in young adults.The diagnosis is established from clinical environment, imaging and histological confirmation.The therapeutic possibilities are limited and the survival close to 2 years showing a high mortality.We report the case of an 11-year-old male patient who was treated at the Central Military Hospital of Bogotá, Colombia where the diagnosis was made and treatment was instituted.