Because of the potential of hybrid rice and its commercial success in China, many countries in Asia, Africa, Latin America, and the Caribbean showed a keen interest in developing and using this technology. The first International Hybrid Rice Observational Nursery (IRHON) was put together in 1994 with 44 hybrids (H), 36 restorers (R), and 5 maintainers (B) developed at IRRI. This nursery was evaluated in Bangladesh (Gazipur), China (Changsha, Hang- zhou), India (Coimbatore, Faizabad, Hyderabad, Kapurthala, Karnal, Mandya, Maruteru, Pantnagar), Myan- mar (Yangon, Yezin), the Philippines (Los Baños, Maligaya), and Sri Lanka (Batalagoda). A number of hybrids that could be adapted in most of these countries were identified. Hybrids IR67693H, IR69672H, IR69684H, IR69686H, and IR69689H were identi- fied as superior and widely adapted. In the second IRHON conducted at 29 locations in 13 countries, 33 hybrids, 3 B lines, and 25 R lines developed in IRRI, China, India, and Myanmar were tested. Hybrids IR67693H, IR64616H, IR68284H, IR68877H, IR69679H, and IR70402H were identified as superior. In the third IRHON, three hybrids from a private company were also included. This nursery is now undergoing testing at 45 locations in 16 countries in Asia, Africa, and Latin America.