The scope of the Encyclopædia is not limited to the geographical boundaries of present-day Persia, but encompasses all the lands where Iranian languages are or were spoken. Afghanistan, Tajikistan, Baluchistan, Kurdistan, the Pathan regions of Pakistan, Parsi communities of India, and Ossetic and Talish regions of Caucasus are thus treated fully; appropriate coverage is also devoted to Central Asia, Mesopotamia, and the Indian Subcontinent, where Persian or another Iranian language (such as Soghdian) has predominated during important periods of their history.

The relations and mutual influences between the Iranian world and other societies, from China to Europe to the United States, also fall within the purview of the Encyclopædia

The time span extends from prehistory to the present. Biographies of living persons, however, are not included. Beside significant individuals and geographic locations, entries include technical terms and concepts related to different disciplines.