This study examines the construction of maslahah in judicial reasoning concerning the cumulation of itsbat nikah and divorce proceedings in Indonesian Religious Courts, focusing on the Bukittinggi and Batusangkar Religious Courts. It addresses the tension between formal marriage requirements, particularly the validity and authority of the marriage guardian (wali nikah), and the need to ensure legal certainty and protection for parties in dysfunctional marital relationships. Employing a normative-empirical legal research design, the study uses statutory, case, conceptual, and comparative approaches. Data were obtained from Decisions No. 452/Pdt.G/2022/PA.Bkt and No. 308/Pdt.G/2023/PA.Bsk, supplemented by semi-structured interviews with judges involved in the respective cases and relevant legal literature. The findings show that both courts constructed maslahah around legal certainty, substantive justice, utility, and prevention of harm despite deficiencies in formal marriage requirements. The Bukittinggi Religious Court explicitly applied istihsan bi al-mashlahah and restricted recognition of the marriage to facilitating divorce. The Batusangkar Religious Court adopted a comparable substantive orientation, although the restriction of itsbat nikah was articulated more clearly in the judicial reasoning than in the operative part of the decision. The study concludes that maslahah functions as a contextual and remedial framework for resolving legally problematic marriages while maintaining normative constraints. It contributes to Islamic family law scholarship by shifting analytical attention from normative-procedural conformity toward judicial reasoning and demonstrating how maslahah mediates between formal legal requirements and the protection of affected parties in contemporary Indonesian Islamic family law adjudication and practice.