The hemodynamic effects of repetitive magnetic stimulation (RMS) of the human brain were investigated by several authors that reported an increase of the cerebral blood flow (CBF). CBF is closely coupled with brain metabolism. To evaluate if CBF changes induced by RMS are associated with metabolic activation we measured the brain oxygen availability and consumption before and after RMS using NIRS (Near Infra-Red Spectroscopy; CRITIKON Cerebral Redox Research Monitor 2001). NIRS is a non invasive technique based on the ability of near infrared light (650-1000 nm) to pass through tissues. We studied 10 healthy volunteers and evaluated cerebral variation in HHb, HbO 2 , and Cit aa3 correlated to magnetic stimulation. The NIRS probe was placed on motor and premotor areas. Magnetic stimulation was performed using a Magstim 200 (Novametrix, UK). Thirty stimuli (100% of the maximal stimulator output; 0.25 Hz) were delivered through a figure of 8 coil over the premotor and motor cortex. The data averaging of 10 minutes recording before and of 5 minutes after the magnetic stimulation were recorded. Immediately after stimulation a significant increase in HbO 2 and a decrease in Cit aa3 was observed (p < 0.05). Our data suggest that RMS induces metabolic activation of the cerebral cortex together with an increase of CBF.