Criticism of Iranian President Mahmoud Ahmadinejad became rampant after his election victory on June 29, 2005. These include charges that he participated in the 1979-1981 Iran Hostage Crisis, assassinations of Kurdish politicians in Austria, torture, interrogation and executions of political prisoners in the Evin prison in Tehran. Ahmadinejad and his political supporters have denied these allegations.
From before the second round of the elections, in late July 2005, there have also been allegations of political corruption from Ahmadinejad's political opponents inside Iran, especially his opponents in the reformist parties.

In voting for storming the US embassy, Ahmadinejad objected, arguing that the protest ought to be directed at the Soviet embassy, but they were outvoted. Ahmadinejad has said that he did not support the embassy takeover until Ayatollah Ruhollah Khomeini endorsed it. The endorsement came late on November 4, 1979, the day the embassy was seized. 
According to al-Jazeera, when OSU leaders proposed taking over the US embassy in 1979, Ahmadinejad proposed taking over the Soviet embassy at the same time.
In 2005, several Former hostages of the 1979 Iranian Hostage Crisis claim that a Basij Militant who frequently interrogated and transported hostages (see Picture) was Iranian President Mahmood Ahmadinejad. This claim which was brought up several weeks after Ahmadinejad's Inauguration, was taken to the FBI and CIA for more Investigation between Ahmadinejad and the person to the hostages left side in the photograph. Although the FBI is still investigating, the CIA currently claims that the man to the hostages left side is not Ahmadinejad and according to known existing photos of Ahmadinejad in the 70's does not match the Looks of the Militant. The FBI however claims, according to their research, this could be Ahmadinjad because there is no clear record of his life from 1978-1981 (Note: the years of the Hostage Crisis). However the FBI cannot use Biometric Iris Identification to match Ahmadinejad's eyes to the man in the picture because the man's eyes are too shielded to provide any clear information.
Ahmadinejad, who was a member of the Basij during the Revolution, denied taking any part in The Hostage Crisis and claims that he was against it from the beginning, although he did admit that he urged the planners of the crisis to take over the Soviet embassy. A reason he cited, was that the USSR was an atheist regime, and he believed it would have reduced MKO resistance in Iran.
This allegation has been denied by several sources in Iran, including Saeed Hajjarian, a political opponent of Ahmadinejad. Also notable among the deniers, is Ali Rabiee, the intelligence advisor to the reformist President Khatami, who stated "during the mentioned accident happened, I was present in action regions of northwest and western Iran, and at that time Mr. Ahmadinejad was only involved at the civil construction work in the governing offices of Maku and the province". At the same time, the allegation has been echoed by a spokesman for the People's Mujahedin of Iran, an opposition group in exile.
Reuters has mentioned that information [Pilz] received from an "extraordinarily credible" informer, an Iranian journalist living in France who Pilz calls only "witness D". [...] Witness D's information came from one of the alleged gunmen, who contacted Witness D in 2001 but later drowned, Pilz said. Supporters of Ahmadinejad have questioned the credibility of such information, have mentioned that Pilz is a Jew, and have called the media reporting these to be "Zionist media." Also, Hamid Reza Asefi, the spokesman of the Iranian Ministry of Foreign Affairs has said that, "The charges are so self-evidently false they are not worthy of response. […] We advise the Europeans not to fall into the trap of the Zionist media and to separate their interests from America and the Zionist entity (referring to the state of Israel).
Also, observers have been skeptical of Pilz's allegations after he refused to disclose any evidence claiming that it would endanger the life of the witness. Also, the accusations have died down after the presidential election, and no clear evidence has been provided that would support the accusations.
Some political groups, including the reformist party Islamic Iran Participation Front (IIPF), allege that Ahmadinejad received illegal support and advertising activities from supervisors selected by the Guardian Council who should have remained nonpartisan according to the election law. Also, the reformist newspaper Shargh pointed out an announcement by Movahhedi Kermani, the official representative of the Supreme Leader in the Islamic Revolutionary Guards Corps, who was quoted as saying, "vote for a person who keeps to the minimum in his advertisements and doesn't lavish," which uniquely pointed to Ahmadinejad, whose supporters touted as being not wealthy.
Popular forms of western music (hip-hop, rock, jazz) have however been banned in Iran for many years, since the days of Khomeini. At the same time, some forms of western music, such as classical music, are regularly aired on state radios.
Since the Iranian Revolution, no Iranian reporters have been allowed to enter the United States or take part in a press conference of the U.S. President. Reporters employed by the state-run IRIB have only been allowed to cover UN events and are only able to travel within a 17 mile radius of New York City. For this reason several IRIB reporters criticised President Ahmadinejad on his support for CNN.
A campaign, led by Iran's Islamist president, Mahmoud Ahmadinejad, attempts to free the country of Western cultural influences, via the Internet. Human rights groups, YouTube and b3ta are amongst the major Web sites blocked. Reporters Without Borders branded Iran, along with 13 other countries, as "enemies of the Internet" in November 2006.
Iran has about 7.5 million Internet users which is the highest number of web users in the Middle East. The country also has more than 100,000 bloggers, some of which are substitutes for Iran's suppressed, reformist press.
Critics accuse Iran of using filtering technology to censor more sites than any country, except the People's Republic of China. Until now, targets have been mainly linked to opposition groups or those deemed "immoral" under Iran's Islamic legal code. Some news sites, such as the BBC's Persian service, are also blocked.
Former CIA officer Robert Baer said, in the context of evaluating a nuclear strike on Iran, that Ahmadinejad and others in the Iranian government are "apocalyptic Shiites." He continues, "If you’re sitting in Tel Aviv and you believe they’ve got nukes and missiles — you’ve got to take them out. These guys are nuts and there's no reason to back off.
Some have conjectured that his actions are strictly a means of bolstering his standing among Islamic fundamentalists.
On September 24, 2007 Ahmadinejad appeared at Columbia University. President Lee Bollinger received harsh criticism for inviting such a controversial figure to Columbia. He responded in a statement saying "The event will be part of the annual World Leaders Forum, the University-wide initiative intended to further Columbia’s longstanding tradition of serving as a major forum for robust debate, especially on global issues, and also for closing the area to outside protesters. . Columbia University's president, Lee Bollinger, introduced Ahmadinejad with a combative tone: "Mr. President you exhibit all the signs of a petty and cruel dictator." Ahmadinejad responded by opening his speech saying that his introduction was "an insult to information and knowledge of the audience there." Some of his arguments were met with derisive laughter, for example "... in Iran we don't have homosexuals, like in your country. We don't have that in our country. In Iran we do not have this phenomenon. I don't know who told you that we have it." An aide later claimed that he was misrepresented and was saying that "compared to American society, we don't have many homosexuals".
He however was applauded when he spoke about the Palestinian peoples' right to self-determination. He spoke on the issue of the September 11, 2001 attacks that "if the root causes of 9/11 are examined properly, why it happened, what caused it, what conditions led to it, who was involved, and put together how to understand and how to prevent the crisis in Iraq, fix the problem in Afghanistan and Iraq combined". He also stated "the most liberated women in the world are the women in Iran". Regarding the Holocaust he said "granted this happened, what does this have to do with the Palestinian people?" He used Koranic quotes to criticize the Bush administration and the bombings of Nagasaki and Hiroshima. He also stated the peaceful nature of Iran's nuclear ambitions. Outside the convention many protested his presence there, most of them supporters of Jewish organizations .