Abstract: A demountable partition assembly comprising a ceiling runner rigidly attached to an upper supporting surface and stabilizer means suspended from said ceiling runner, the stabilizer means receiving and providing lateral support to the upper portion of wall panels hung on the opposed sides of the stabilizer means. The partition assembly is supported at the bottom by support members which permit leveling of the members to be parallel to the ceiling runner, with the bottom surface of the walls being formed with grooves for engagement by tongues formed on finish base members attached to said support members.