It is important to be considered in which way is allocated the jurisdiction between a domestic court and an arbitral tribunal and how to resolve the conflict of competence. Arbitral proceeding will only be allowed in case it is based on a valid and effective arbitration agreement. Nevertheless, judicial power to review arbitral jurisdiction has to be restricted. Excessive court's intervention in arbitration undermines both party autonomy and the efficiency of arbitration and can cause relinquishment of the right to arbitrate. Indeed, it is not uncommon that a court's jurisdiction is invoked by a claimant as a dilatory tactic, however, a party can be noncommittal about arbitration, simply observing an arbitration agreement as null and void, inoperative or incapable of being performed. If a party commences a court proceeding, the party insisting on the enforcement of the arbitration agreement can invoke the parties' agreement to arbitrate as a defense before the national court. If the respondent fails to file a plea before making submissions on the merits the domestic court's lack of jurisdiction is healed. In case that defendant provides arbitration agreement, there is a presumption that the arbitration is competent, unless it is evident that agreement is null and void, inoperative or incapable of being performed. The role of the domestic court in this proceeding has to be limited and restricted. In Serbia, the protective barriers between arbitration and national court systems are the New York Convention and Serbian Law on Arbitration. Domestic courts have frequently been in a position to rule on the objection of lack of jurisdiction, and this paper analyzes how the courts dealt with conflict of competence. Several following issues have been identified, issues that the commercial courts and the Serbian Supreme Court of Cassation had to address in order to decide on the validity of the arbitration agreement. Furthermore, due to the fact that one of the main goal in the arbitration field is the harmonization of the laws as well as the case law, the author provides some guidelines and conclusions so that the Serbian courts can more confidently respond to these challenges.