Dispute resolution in construction services has complex characteristics because it involves various parties, detailed contract documents, and technical and financial risks. Arbitration is one of the dispute resolution methods recognized in Indonesia, as regulated in Law Number 30 of 1999 concerning Arbitration and Alternative Dispute Resolution. In arbitration, the decision is final and binding, but the mechanism for annulling arbitration decisions in Indonesia, especially based on Article 70, is often a loophole that can be used by certain parties to challenge arbitration decisions on the grounds of public order. This is different from international practices regulated in the 1958 New York Convention, which provides more protection for arbitration decisions so that they can be executed effectively. This study analyzes the validity of arbitration decisions in resolving construction service disputes with a case study of Bintang Express Sarana vs. PT Wijaya Karya Realty. In addition, this study also evaluates the effectiveness of the mechanism for annulling arbitration decisions in Indonesia in providing legal certainty and comparing it with international standards. The results of the study show that the application of Article 70 often creates legal uncertainty due to the broad interpretation of public order, thus weakening the effectiveness of arbitration as a dispute resolution mechanism. Regulatory reform is needed to align arbitration practices in Indonesia with international standards, provide better protection for arbitral awards, and ensure that arbitration can function as an efficient and credible alternative in resolving construction service disputes.