This Health Technology Assessment Report has been prepared on the basis of available information of which the Foundation is aware from public literature and expert opinion, and attempts to be current to the date of publication. Posteroventral pallidotomy (PVP) is a neurosurgical procedure which has been used to treat Parkinson's Disease patients whose symptoms are no longer adequately controlled by medication. Perhaps 700 persons in Alberta would be potential candidates for the procedure. PVP is symptomatic treatment and does not halt progression of the disease or replace the need for medication. Several trials have shown that PVP can be effective in relieving symptoms. The quality of the available evidence is fair to poor and there are few data on long-term outcomes. PVP is associated with complications, though these should be regarded in the context of the severity of the disease in those who are candidates for the procedure. Economic data for the procedure in Alberta are not available. However, hospital stays for PVP are expected to be brief, and alternative medical treatment may be costly. The procedure should be regarded as an evolving technology, with uncertain outcomes, until further data become available.