Rhythmicity is an essential temporal component of movement strictly embedded in many motor control functions. The timing process appears to be coded in a distributed network of brain regions depending upon task specifics. The present study attends to investigate by transcranial magnetic stimulation (TMS) the role of different neural structures in the finger tapping test at different conditions. Nine healthy right-handed subjects participated in the main experiment. rTMS (10 min. 90% of resting motor threshold) was applied over the right and left cerebellar hemisphere (RCH, LCH) and ipsilateral primary motor area (M1) in three different sessions. In each session subjects were asked to tap on the surface of a force transducer with their right index finger in synchronization with an auditory cue at 0.5, 1 and 2 Hz, before rTMS, after rTMS and 15 min after rTMS. The ANOVA show a significant impairment in the variability in the intertap intervals (ITI) (P<0.02) and in the mean accuracy at 2 Hz (P0.04) without any effect onthe SMA. These results support the hypothesis of neural network for timing process specific to the characteristics of the task such as the presence and nature of the cue and the duration of the range time.