Colloid cyst is a rare benign intracranial neoplasm, commonly located in the third ventricle. Though headache and visual symptoms are classical, the patients may present with sudden neurological deterioration. We present a ten-year-old male child who presented with sudden neurological deterioration due to colloid cyst of the third ventricle resulting in death. The child had intermittent headache for three months, for which medical attention was not sought. This report details the case and a short review of the condition is presented (with emphasis on the clinical features and importance of early diagnosis). Management (including surgical methods and conservative treatment) of third ventricle colloid cysts is briefly reviewed.