The authors studied 577 records of rheumatoid arthritis examined radiologically in the Department of Radiology B of Cochin Hospital: 165 patients showed evidence of lesions of the cervical spine. The risk of cervical involvement in rheumatoid arthritis is thus not negligeable: 28%. This involvement may occur at any time during the course of the disease and presents as pain or by rare and more or less slight neurological manifestations. Radiologically emphasis must be placed upon the orientation points of straight and lateral films, and the value of lateral films with the neck in flexion. Atlanto-axial dislocation is the commonest lesion, usually measured by the distance separating the anterior arch of the atlas from the odontoid peg. However, other lesions are possible, in particular involvement of the lateral masses and erosion or destruction of the odontoid. It is astonishing to discover large dislocations (of up to 10 mm) which remain well-tolerated, with minimal clinical signs. However, it is the neurological risk of quadriplegia (even though minimal) which remains the constant worry since it may result from the slightest trauma or forced movement of the neck. Fixation, usually posterior occipital C1-C2, may be indicated. It is thus necessary to carry out a routine radiological examination of C1-C2 at reasonable intervals during the clinical surveillance of a patient with rheumatoid arthritis.