A series of 75 patients who had undergone anterior cervical fusion between 1965 and 1977 were reviewed. The patients were divided into two groups: those in Group A had had the level of fusion indicated by cine radiography, whereas in Group B the level had been determined by plain radiographs and clinical symptoms and signs. Results showed that cine radiography was the more accurate diagnostic technique. Accurate diagnosis of the level to be fused, the careful clinical selection of patients and sound bony union were found to be vital to the success of anterior cervical fusion. The incidence of pseudarthrosis was significant in single-level fusions and was even greater in double-level fusions and in patients with a history of trauma, especially whiplash injuries. It was rare to develop recurrence of symptoms in adjacent levels after fusion of a level localised by cine radiography.