Mucopolysaccharidosis (MPS) Type VI, or Maroteaux-Lamy syndrome, is characterized by a deficiency of the enzyme arylsulfatase B (ASB). In patients with this disorder, craniocervical compression, carpal tunnel syndrome, and communicating hydrocephalus are common. Traditionally, hydrocephalus occurring in patients with MPS VI has been treated with shunt placements. Considering obstruction of the outlets from the fourth ventricle at the craniocervical transition, the authors decided to treat a female patient with MPS VI via endoscopic third ventriculostomy. She was 12 years old and had refractory headaches. This seems to be the first reported instance of the neuroendoscopic treatment of hydrocephalus in a patient with MPS VI. The pathophysiology is briefly discussed.