In 62 patients undergoing posteroventral pallidotomy (PVP) for the treatment of Parkinson's disease, we have demonstrated significant (p < 0.01) elimination of akinetic features and other symptoms during intraoperative stimulation trials in areas anterior to the PVP target (n = 30). Stimulation in anterior pallidal regions frequently resulted in an immediate reversal of akinetic states despite enforced abstinence of medications. The beneficial effects were achieved with as little as 0.25 V at 100 Hz. Stimulation at the PVP target site (n = 32) resulted in insignificant changes (p > 0.05).