Following spinal cord injury (SCI), there is a natural reduction in motor intracortical inhibition (ICI) (Smith et al. 2000). Recently, we have shown that a specific pattern of repetitive transcranial magnetic stimulation (rTMS) leads to a reduction in ICI, a decrease in cutaneous perceptual threshold and to improvements in a functional test and clinical scores in incomplete SCI (Belci et al. 2004). Now, we evaluate the effect of this rTMS protocol in a group of healthy subjects. With local ethics approval and consent, six healthy adult subjects were recruited. The rTMS pattern used was a doublet stimulus (100ms interval) applied every 10s for 30 min. Stimuli were delivered using a Magstim 200 stimulator connected to a 9cm circular coil centred over the vertex, A-side up, and at 90% of the resting motor threshold for the right thenar muscle. Before, during and after the rTMS, surface electromyography was recorded from right and left thenar muscles during 20% maximum voluntary contraction while single pulse TMS was employed as appropriate to elicit motor evoked potentials (MEP) and ICI in the right or left hand. Perceptual threshold (PT) to electrical stimulation of the right and left C6 dermatomes was also assessed using a Digitimer Stimulator-DS7. Measurements were made at intervals for two hours after rTMS. Statistical analysis was performed using repeated measures ANOVA with Holm-Sidak post hoc test. In the right hand, there were significant decreases in ICI (P=0.016) and PT (P<0.001) following rTMS. Post-hoc test showed that ICI was decreased 10 minutes after the start of rTMS while PT was decreased at 60, 90 and 150 min. Mean values of ICI and PT had not recovered to baseline values after 2 hours. rTMS had no significant effect on MEP size (P=0.90). In the left hand, there were no significant changes in ICI (P=0.16) or MEP size (P=0.25) following rTMS. However, PT was lowered (P=0.006) at 30 and 60 min after start of rTMS. Our findings suggest that the sub-threshold rTMS pattern that we have used has demonstrable motor and sensory effects on healthy subjects. The mechanism is thus not dependent on the plastic changes present in subjects with spinal cord injury.