The specimen was found in dark red sandstone of the Nam Phong Formation near the village of Ban Non Thaworn, in Chaiyaphum Province. When discovered in 1998, the skeleton had unfortunately been mostly eroded away. With regard to vertebrate fossils, the Nam Phong Formation is poorly explored: besides "Isanosaurus", only two articulated ischia were found. Whether these ischia belong to "Isanosaurus" is unclear, because no pelvic bones are preserved in the holotype specimen. "Isanosaurus" was described by French palaeontologist Éric Buffetaut and colleagues in 2000. The name is derived from Isan (north-eastern Thailand); the species name honours P. Attavipach, a supporter of palaeontological research in Thailand and former Director General of the Thai Department of Mineral Resources.