Arbitration has become, to a large extent, more expensive, slower and less final than it once was. Party challenges to arbitration awards in court are partly responsible for this. Certainly, these challenges reduce the certainty that the arbitral decision is final and binding, as had been negotiated by the parties. The purpose of this chapter is to identify the characteristics of labor and employment arbitration cases in which the losing party has challenged the award, and in particular, those cases where the award was eventually vacated, usually based on an act or omission by the arbitrator.