Indonesia is one of the members of the World Trade Organization that took part in ratifying the World Trade Organization Agreement on Technical Barrier to Trade (WTO-TBT) through Law Number 7 of 1994 on Agreement of Establishing the World Trade Organization (PWTO Law). In accordance with PWTO Law, Indonesia is required to implement the trade regulations, including technical infrastructures such as metrology. The objective of this study is to examine the harmonization of law in the field of metrology as a consequence of the WTO-TBT Agreement. This research applied a juridical normative and descriptive analysis method. The data were obtained by conducting a literature review. The study showed that the legal consequence of WTO-TBT on the metrology regulation had discovered the need to harmonize the Law Number 2 of 1981 on Metrology with various regulations. Many regulations and international organizations are involved since the establishment of WTO-TBT concerning accurate measurements in the field of metrology. In conclusion, the cooperation of various countries under the framework of the WTO obliges Indonesia to harmonize its trade and metrology law. Such harmonization should also cover the rules at a regional level.