Tax arbitration? Yes, that would be a very good idea... Yet the trend in different tax treaties to introduce mechanisms of dispute reslution labelled 'arbitration' immediately raises a very basic doubt: is this arbitration at all? The question is not a matter o semantics. Whether a mechanism of dispute resolution is considered arbitration in the legal sense affects the power of arbitrators to rule on their own jurisdiction, or to organize the proceedings, as well as the enforceability of the decision, or the evaluation of whether the procedure respected fundamental rights. The chapter examines all these uetsions in detail, concluding that, as convenient as tax treaty dispute resolution mechanisms may be for tax authorities, they are (extremely) short on safeguards for the taxpayer.