While population estimates in Azerbaijan are considered reliable due to regular censuses, the figures for Iran remain questionable.
Since the early twentieth century, successive Iranian governments have avoided publishing statistics on ethnic groups.
Unofficial population estimates of Azerbaijanis in Iran are around the 16% area put forth by the CIA and Library of Congress.
An independent poll in 2009 placed the figure at around 20–22%.
Nevertheless, regardless of the highest or lowest estimates or publications, Azerbaijanis in Iran comprise by far the second-largest ethnic group in the nation as well as by far the largest minority ethnic group.
Furthermore, once again regardless of any estimate or publication, the number of Azerbaijanis in Iran by far outnumber the amount of Azerbaijanis in the neighboring Republic of Azerbaijan, and comprise the largest number of ethnic Azerbaijanis in the world.

Azerbaijanis in Iran are mainly found in the northwest provinces: West Azerbaijan, East Azerbaijan, Ardabil, Zanjan, parts of Hamadan, Qazvin, and Markazi.
Azerbaijani minorities live in the Qorveh and Bijar counties of Kurdistan, in Gilan, as ethnic enclaves in Galugah in Mazandaran, around Lotfabad and Dargaz in Razavi Khorasan, and in the town of Gonbad-e Qabus in Golestan.
Large Azerbaijani populations can also be found in central Iran (Tehran # Alborz) due to internal migration.
Azerbaijanis make up 25% of Tehran's population and 30.3%  – 33% of the population of the Tehran Province, where Azerbaijanis are found in every city.
They are the largest ethnic groups after Persians in Tehran and the Tehran Province.
Many Azerbaijanis have emigrated and resettled in large numbers in Khorasan, living beside linguistically related Khorasani Turks, especially in Mashhad.

Generally, Azerbaijanis in Iran were regarded as "a well integrated linguistic minority" by academics prior to Iran's Islamic Revolution.
Despite friction, Azerbaijanis in Iran came to be well represented at all levels of "political, military, and intellectual hierarchies, as well as the religious hierarchy".

Resentment came with Pahlavi policies that suppressed the use of the Azerbaijani language in local government, schools, and the press.
However, with the advent of the Iranian Revolution in 1979, emphasis shifted away from nationalism as the new government highlighted religion as the main unifying factor.
Islamic theocratic institutions dominate nearly all aspects of society.
The Azerbaijani language and its literature are banned in Iranian schools.
There are signs of civil unrest due to the policies of the Iranian government in Iranian Azerbaijan and increased interaction with fellow Azerbaijanis in Azerbaijan and satellite broadcasts from Turkey and other Turkic countries have revived Azerbaijani nationalism.
In May 2006, Iranian Azerbaijan witnessed riots over publication of a cartoon depicting a cockroach speaking Azerbaijani that many Azerbaijanis found offensive.
The cartoon was drawn by Mana Neyestani, an Azeri, who was fired along with his editor as a result of the controversy.
One of the major incidents that happened recently was Azeris protests in Iran (2015) started in November 2015, after children's television programme Fitileha aired on 6 November on state TV that ridiculed and mocked the accent and language of Azeris and included offensive jokes.
As a result, hundreds of ethnic Azeris have protested a program on state TV that contained what they consider an ethnic slur.
Demonstrations were held in Tabriz, Urmia, Ardabil, and Zanjan, as well as Tehran and Karaj.
Police in Iran have clashed with protesting people, fired tear gas to disperse crowds, and many demonstrators were arrested.
One of the protesters, Ali Akbar Murtaza, reportedly "died of injuries" in Urmia.
There were also protests held in front of Iranian embassies in Istanbul and Baku.
The head of the country's state broadcaster Islamic Republic of Iran Broadcasting (IRIB) Mohammad Sarafraz has apologized for airing the program, whose broadcast was later discontinued.

Azerbaijanis are an
While population estimates in Azerbaijan are considered reliable due to regular censuses, the figures for Iran remain questionable. Since the early twentieth century, successive Iranian governments have avoided publishing statistics on ethnic groups. Unofficial population estimates of Azerbaijanis in Iran are around the 16% area put forth by the CIA and Library of Congress. An independent poll in 2009 placed the figure at around 20–22%. Nevertheless, regardless of the highest or lowest estimates or publications, Azerbaijanis in Iran comprise by far the second-largest ethnic group in the nation as well as by far the largest minority ethnic group. Furthermore, once again regardless of any estimate or publication, the number of Azerbaijanis in Iran by far outnumber the amount of Azerbaijanis in the neighboring Republic of Azerbaijan, and comprise the largest number of ethnic Azerbaijanis in the world.
Azerbaijanis in Iran are mainly found in the northwest provinces: West Azerbaijan, East Azerbaijan, Ardabil, Zanjan, parts of Hamadan, Qazvin, and Markazi. Azerbaijani minorities live in the Qorveh and Bijar counties of Kurdistan, in Gilan, as ethnic enclaves in Galugah in Mazandaran, around Lotfabad and Dargaz in Razavi Khorasan, and in the town of Gonbad-e Qabus in Golestan. Large Azerbaijani populations can also be found in central Iran (Tehran # Alborz) due to internal migration. Azerbaijanis make up 25% of Tehran's population and 30.3%  – 33% of the population of the Tehran Province, where Azerbaijanis are found in every city. They are the largest ethnic groups after Persians in Tehran and the Tehran Province. Many Azerbaijanis have emigrated and resettled in large numbers in Khorasan, living beside linguistically related Khorasani Turks, especially in Mashhad.
Generally, Azerbaijanis in Iran were regarded as "a well integrated linguistic minority" by academics prior to Iran's Islamic Revolution. Despite friction, Azerbaijanis in Iran came to be well represented at all levels of "political, military, and intellectual hierarchies, as well as the religious hierarchy".
Resentment came with Pahlavi policies that suppressed the use of the Azerbaijani language in local government, schools, and the press. However, with the advent of the Iranian Revolution in 1979, emphasis shifted away from nationalism as the new government highlighted religion as the main unifying factor. Islamic theocratic institutions dominate nearly all aspects of society. The Azerbaijani language and its literature are banned in Iranian schools. There are signs of civil unrest due to the policies of the Iranian government in Iranian Azerbaijan and increased interaction with fellow Azerbaijanis in Azerbaijan and satellite broadcasts from Turkey and other Turkic countries have revived Azerbaijani nationalism. In May 2006, Iranian Azerbaijan witnessed riots over publication of a cartoon depicting a cockroach speaking Azerbaijani that many Azerbaijanis found offensive. The cartoon was drawn by Mana Neyestani, an Azeri, who was fired along with his editor as a result of the controversy. One of the major incidents that happened recently was Azeris protests in Iran (2015) started in November 2015, after children's television programme Fitileha aired on 6 November on state TV that ridiculed and mocked the accent and language of Azeris and included offensive jokes. As a result, hundreds of ethnic Azeris have protested a program on state TV that contained what they consider an ethnic slur. Demonstrations were held in Tabriz, Urmia, Ardabil, and Zanjan, as well as Tehran and Karaj. Police in Iran have clashed with protesting people, fired tear gas to disperse crowds, and many demonstrators were arrested. One of the protesters, Ali Akbar Murtaza, reportedly "died of injuries" in Urmia. There were also protests held in front of Iranian embassies in Istanbul and Baku. The head of the country's state broadcaster Islamic Republic of Iran Broadcasting (IRIB) Mohammad Sarafraz has apologized for airing the program, whose broadcast was later discontinued.
Azerbaijanis are an 
Azerbaijanis