Large changes in somatotopic organization can be induced in adult primate somatosensory cortex by cutting peripheral afferents. The role, if any, of the thalamus in these changes has not been investigated previously. In the present experiments, electrophysiological recording in the ventroposterior lateral nucleus (VPL) has revealed that not only can reorganization occur in the thalamus, but it may be as extensive as that revealed in the cortex of the same monkeys. Thus, for at least some types of deafferentation, the reorganization revealed in the cortex may depend largely on subcortical changes.