Event Related Potentials (ERP) were recorded using a 32 channel system in a modified 10-20 system. We compared unilateral movements of digits and toe with motor imagery of the same movements in a visually cued task. A distinct biphasic pattern of electrical activity following cue onset was observed. It was composed by a first peak at a latency of 140 msec and a second peak at 240 msec in both the imagined and executed task. The first peak corresponded to the visual evoked potential and was the same in the two conditions. The second peak was significantly large in the executed movement. Source analysis revealed that both peaks could be modelled by a single dipole and revealed no qualitative difference between tasks. These data suggest that imagined movement is not sustained by the contribution of cortical regions different from those responsible of the executed one.