The present report describes a patient with rheumatoid arthritis and vertical atlanto-axial subluxation who developed hydrocephalus with high intraventricular pressure and neuropsychiatric abnormalities. The vertical atlanto-axial subluxation and hydrocephalus were visualized by magnetic resonance imaging, which clearly demonstrated the basilar impression by the dens and ventricular enlargement. The patient recovered completely after ventriculo-cardial drainage.