Background: Stimulation frequency has been considered a crucial determinant of efficacy in deep brain stimulation (DBS). DBS at frequencies over 250Hz is not currently employed and consensus in the field suggests that higher frequencies are not clinically effective. With the recent demonstration of clinically effective ultra-high frequency (UHF) spinal cord stimulation at 10kHz we tested whether UHF stimulation could also be clinically useful in movement disorder patients with DBS. Methods: We studied the effects of conventional (130Hz) and UHF stimulation in five patients with Parkinson’s disease (PD) with STN DBS and in one patient with essential tremor (ET) with VIM DBS. We compared the clinical benefit and adverse effects of stimulation at various amplitudes either intraoperatively or postoperatively with the electrodes externalized. Results: Motor performance improved in all six patients with UHF DBS. 10kHz stimulation at amplitudes ≥3.0mA appeared to be as effective as 130Hz in improving motor symptoms (46.2% vs 53.5% motor score reduction, p=0.110, N=90 trials). Interestingly, 10kHz stimulation resulted in fewer stimulation-induced paresthesiae and speech adverse effects than 130Hz stimulation. Conclusions: Our results indicate that DBS at 10kHz produces clinical benefits while possibly reducing stimulation-induced adverse effects in patients with movement disorders.