Persian (called fārsi in Persian, فارسی), an Indo-European language, is Iran's national and official language. Although written with a modified Arabic alphabet, the two languages are not related but Persian does have many loan words from Arabic.

Many young Iranians in major cities, and almost certainly those working in international travel agents and high-end hotels will speak conversational English but basic Persian phrases will definitely come in handy, particularly in rural areas.

Road signs are often double signed in English, but few other signs are. As an extra challenge, most Persian signage uses an ornate calligraphic script that bears little resemblance to its typed form. This can make comparing typed words in phrase books--such as 'bank' and 'hotel'--to signs on buildings quite difficult. However it is still worth memorising the Persian script for a few key words such as restaurant, guesthouse, and hotel (see relevant sections below for the script).

Be aware that Kurdish and Azeri languages are also spoken in areas of large Kurdish and Azeri populations.