The history of Euro-Asian Cooperation of State Metrological Institutions (COOMET) began three decades ago, on June 12, 1991, when the COOMET Memorandum of Understanding was signed. COOMET is an officially recognized regional organization on metrology, as well as a regional organization on legal metrology. Cooperation in COOMET allows its member countries to successfully solve urgent metrological problems facing the national economies in the context of market globalization, as well as to integrate into the international metrological system. This article briefly reviews the history of COOMET and its major achievements. An assessment of the COOMET effectiveness is given, and promising directions of COOMET development are outlined.