The Arnold-Chiari malformation(ACM) is an anomaly of the hindbrain consisting of two components : a variable displacement of a tongue of tissue derived from the inferior cerbellar vermis in the upper cervical cannal and a similar caudal dislocation of the medulla and fourth ventricle. Hydrocephalus and meningomyelocele are another abnormalities that associated frequently. We present a case of Arnold-Chiari malformation with hydrocephalus and meningomyeolcele and a brief review of the literatures was added.