Progressive walking difficulties and bladder dysfunction may be attributed to Alzheimer disease or atlanto-axial subluxation in people with Down's syndrome (DS). The present authors describe five patients with DS suffering from the above symptoms as a result of cervical spondylarthrotic myelopathy. Clinical and radiological data were collected from all patients with DS who underwent surgery for cervical spondylarthrotic myelopathy at the Leiden University Medical Centre during the period between 1991 and 1995. Five patients with DS (four males and one female) were identified. Their mean age at diagnosis was 42 years. The main clinical features were weakness of the arms and legs, ataxic gait, hyperreflexia and bilateral Babinski signs. Radiological examination showed spondylarthrosis, compression of the spinal cord and myelomalacia. The mean delay in diagnosis was 3 years. All five individuals showed clinical stabilization after laminectomy. Cervical spondylarthrotic myelopathy seems a rather frequent disorder in DS, occurring at a relatively young age. Early diagnosis may prevent irreversible neurological deficits.