Most patients who have suffered spinal cord injuries now expect a normal life span, so the late complications of these injuries are becoming increasingly frequent. Regular surveillance of the state of the urinary tract and the treatment of impending, even if clinically silent, complications is a well-established aspect of follow-up. With an increasing ability to diagnose and treat the neurological complications, surveillance of the state of the spinal cord has now assumed great importance. Magnetic resonance imaging (MRI), or computerized tomography (CT) with myelography if MRI is contra-indicated is the method of choice and can demonstrate the pathology with great clarity. In most patients, midline sagittal T1 W images are sufficient for screening purposes and for monitoring the success of treatment. Operative, imaging and post-mortem studies have shown that the two main changes that occur are: (a) atrophic and (b) cystic - the microcystic and myxoid gel changes of myelomalacia, focal cysts and the larger, more expansive, syringomyelia. As yet, there is no standardization of terminology to describe the various pathological and radiological states. This is critical as only one condition, syringomyelia, is currently amenable to definitive surgery and without conformity, comparisons of incidence in different populations and assessment of the results of surgery are impossible. The published small studies of predominantly symptomatic patients at varying stages of chronicity give differing incidences of changes. Preliminary results of a surveillance MRI study of the spinal cord changes in 153 patients who had had a spinal cord injury over 20 years previously are presented. Atrophy was present in 62%, myelomalacia in 54%, syringomyelia in 22%, focal cysts in 9% and disruption in 7%.