There is increasing evidence that reorganizational changes in the somatosensory system are, at least in part, induced and maintained by the activation of nociceptive inputs. In this study we assess the relationship between chronic pain and plasticity in cortex and subcortical structures by recording somatosensory-evoked potentials (SEPs) in patients who complain unilateral cervical radicular pain. Twenty subjects were assessed clinically, routine laboratory investigations, plain X-ray and MRI of the cervical spine were performed. Somatosensory evoked potential studies after digital nerve stimulation, nerve conduction studies and electromyography (EMG) were done. The results of SEP studies for patients were compared to those of 10 age and sex matched control subjects. SEPs evoked by stimulation of digital nerves of the painful thumb were compared to those obtained after stimulation of the non-painful thumb and little finger on painful & non-painful sides and to those from control group. EMG evidence of deafferentation was absent in 75% of patients. Amplitudes of EP, N13, N20 and P22 potentials after stimulation of the painful thumb were greater than those of the non-painful thumb, little finger on painful and non painful sides and those of controls. The amplitude difference of EP showed the least change relative to other potentials among patients. Right–left asymmetry was absent after stimulation of the patients’ little fingers and in control subjects. Higher amplitudes of N13, N20 and P22 were associated with higher grade of pain severity. Amplitudes of N13 and N20 were positively correlated with duration of pain. Results suggest that pain can induce neuroplastic changes involving “both” the peripheral and the central levels but more evident centrally.