The finality and stability of judicial decisions constitute fundamental elements of legal certainty and play a vital role in maintaining public confidence in the judicial system. Achieving these objectives requires adherence to the principles governing civil procedure, including defensive order, the prohibition of repetitive litigation, the principle of stability of judicial decisions, and the prevention of abuse of the right to bring legal actions. These principles not only contribute to the effective administration of justice but also ensure procedural fairness, consistency in judicial practice, and the protection of the legitimate expectations of litigants.Within this framework, the present article adopts an analytical and critical approach to examine the judgment of Branch 24 of the Mohammadshahr Karaj General Civil Court. It analyzes the court's treatment of a claim which, despite being presented under different legal titles, was essentially based on the same underlying dispute and had effectively been brought to undermine the legal effects of a previously finalized judgment. The study further explores the relationship between defensive order, procedural good faith, and the doctrine of res judicata in order to determine whether these principles justify restricting repetitive litigation and preventing the reopening of disputes that have already been conclusively resolved.The principal research question is whether the court's decision to declare the subsequent action inadmissible can be justified on the basis of the principles of defensive order, the authority of final judgments, and the necessity of preserving the stability and legal certainty of legal relationships. Accordingly, the study evaluates the legal reasoning adopted by the court in support of its decision through an examination of relevant legal doctrines and procedural principles.The findings indicate that, by emphasizing respect for final judgments, preventing the issuance of conflicting decisions, and prohibiting the relitigation of the same dispute under different legal characterizations, the court acted consistently with the objectives of preserving defensive order and safeguarding the finality and effectiveness of judicial proceedings. This approach not only prevents unnecessary delays in litigation, reduces costs imposed on litigants, and avoids the excessive accumulation of cases before the courts, but also enhances the predictability of judicial decisions, promotes procedural discipline, and strengthens the credibility of the judicial system. Accordingly, the judgment under review may be regarded as a well-founded example of the implementation of the principles governing the finality of judgments and the reinforcement of defensive order in civil proceedings, thereby promoting the efficiency, consistency, and integrity of the administration of justice.