Sports arbitration be defined as a method of resolving sport-related disputes by a final and binding arbitral decision. The Court of Arbitration for Sport (CAS) is the pinnacle of the worldwide dispute settlement system for sport matters. The purpose of CAS is to take international sports disputes out of national courts and provide a highly specialized forum where those disputes could be heard and decided, quickly and inexpensively, according to a a flexible procedure. Setting aside and revision proceedings against the arbitral awards of CAS may only be filed with the Swiss Federal Tribunal due to the seat of CAS tribunals being in Lausanne and these to the CAS arbitrations are governed by Chapter 12 of Swiss Federal Private International Law Act(PILA). Chapter 12 of the PILA regulates international arbitration, defined as arbitral proceedings seated in Switzerland where, at the time of the conclusion of the arbitration agreement, at least one of the parties did not have its domicile or habitual residence in Switzerland. According to Art. 190 PILA, the arbitral awards of CAS can be set aside upon certain specific grounds. The only grounds allowed are those spelled out in Art. 190(2) PILA: if (i) the arbitral tribunal was not properly constituted, (ii) the arbitral tribunal wrongly accepted or declined jurisdiction, (iii) the arbitral tribunal ruled beyond the claims submitted to it, or failed to decide one or more of the claims submitted to it, (iv) the parties’ fundamental procedural rights were breached, or (v) the award is incompatible with public policy. In addition, a party may ask the Swiss Federal Supreme Court to revise the arbitral awards of CAS in according to Art. 190a PILA. The revision of an award is only possible in three circumstances: (i) when a party after notification of the award discovers significant facts or decisive evidence that it could not submit in the arbitration proceedings despite applying the required due diligence; (ii) in the event that criminal proceedings have established that the arbitral award was influenced to the detriment of a party by a criminal act; and (iii) in the event that a ground to challenge an arbitrator is discovered only after the award is rendered and if no other recourse against the award is available. The purpose of the present article is to discuss the important questions that arise in the context of setting aside and revision proceedings before the Swiss Federal Tribunal against arbitral awards of the Court of Arbitration for Sport(CAS).