Dehkhoda Lexicon Institute is the first organization in Iran which as established to compile Persian lexicon in January 1945; almost 30 years after Dehkhoda planned to compile it at his house on Iranshahr Street, Tehran, with the approval of the National Assembly. After Dehkhoda passed away in 1955, the organization was moved next to the Parliament building in Baharestan Square. According to Dehkhoda’s will, Dr. Mohammad Mo’in became the Head of the Organization and other Dehkhoda’s companions, namely Dr. Mohammad Dabir Siaghi and Dr. Mohammad Jafar Shahidi assisted him. In December 1957, according to an Act of Parliament, the organization was transferred to the Faculty of Literature in the University of Tehran with an allocated budget and the members of the Lexicon Institute continued their job in the Negarestan building in Baharestan Square. In 1974, the late Dr. Mahmoud Afshar, endowed one of his buildings to Dehkhoda Lexicon. Compilation of the 50 volumes of the Lexicon was ended in 1980. More than a hundred members cooperated with the Institute in compiling, note taking and setting memoranda whose names have been fully introduced in the preface. The edition and computer typography of this great national work was completed in 1990 and was published in 16 volumes in 1994 and in 15 volumes in 1998. Its CDs became available for the interested people in 1999.