Non-invasive brain stimulation techniques, such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are able to alter the excitability of brain pathways. Applying these techniques over the motor cortex, improved motor function in different patient groups, including stroke and PD (Benninger et al. 2010). Only two studies have investigated the effect of modulation of cerebellar-motor cortex excitability on motor function in PD patients. That is, 1 Hz repetitive TMS (inhibitory rTMS) over the cerebellum improved gross arm movements, but worsened fine motor skills17. Furthermore, a two-week continuous theta burst stimulation TMS protocol decreased levodopa-induced dyskinesias (Koch et al. 2009). These studies only investigated the effects on the upper extremities. The cerebellum is also hyperactive during gait (Hanakawa et al. 1999; del Olmo et al. 2006), but whether modulation of cerebellar excitability can improve gait deficits in PD patients is currently unknown.