1. A diagnosis of upward translocation of the dens was made in eight patients with chronic rheumatoid arthritis selected from a group of patients who had radiographic studies of the cervical spine and from whom a number of patients with atlanto-axial subluxation were also identified.

2. Two of the patients presented with an acute neurological syndrome of serious import and required a stabilisation operation. Though this is an uncommon complication of rheumatoid arthritis it seems that urgent neurological syndromes are likely to be more common than in atlanto-axial subluxation.

1. This paper presents the neurological findings in forty-one patients with rheumatoid arthritis complicated by atlanto-axial subluxation.

2. A method of radiological measurement of the subluxation is described. The extent of neurological involvement was found not to correspond with the degree of subluxation.

3. Fusion of the atlanto-axial complex or of the occipito-atlanto-axial complex is indicated only in patients with progressive neurological signs and in those suffering from acute neurological episodes.

4. Difficulty in obtaining fusion with cancellous bone grafts alone was encountered and we recommend wiring of the laminae C.1 to C.2 in addition.