Measurement is a crucial initial step in the land registration process, as stipulated in Article 19 paragraph (2) letter a of the Basic Agrarian Law (UUPA). Article 17 of Government Regulation No. 24 of 1997 on Land Registration emphasizes that measurements must be supported by physical data and boundary arrangements based on the agreement of adjacent landowners. One key principle in this process is the contradictoire delimitatie principle, which requires the presence of interested parties during the determination of land boundaries. This thesis aims to analyze the function of contradictoire delimitatie in the measurement results of the Complete Systematic Land Registration Program (PTSL), as well as to examine the legal consequences if this principle is not implemented. The study is expected to contribute to the development of legal knowledge in the field of land affairs and serve as a reference for academics, legal practitioners, judicial institutions, law enforcement officials, and land authorities. In practice, if the subject of a land parcel is unknown, information is obtained from neighboring landowners, community leaders, or relevant officials, and recorded in the Measurement Sketch (Gambar Ukur or GU). If boundary agreements have not been reached, dotted lines are used to indicate temporary boundaries. When the Work Map is attached to the GU, the landowner or their representative may sign it as a form of boundary agreement. The absence of the contradictoire delimitatie principle hinders the measurement process, map creation, land registration, and issuance of land rights certificates. Furthermore, unclear or poorly maintained boundaries often lead to overlapping claims and disputes in the field.