Iveri made her debut In December 2011 at the La Scala in Milan, as Donna Anna in Don Giovanni under Daniel Barenboim. She has since performed with the Vienna State Opera, the Metropolitan Opera, the Royal Opera House Covent Garden, Opéra Bastille, and at the Salzburg Festival. A soprano, she has sung the roles of Fiordiligi in Così fan tutte, Vitellia in La clemenza di Tito, Elettra in Idomeneo, Elisabetta in Don Carlos, Amelia in Simon Boccanegra, Desdemona in Otello, Mimì in La bohème, Tatyana in Eugene Onegin and the title roles in Adriana Lecouvreur and Suor Angelica.
Iveri has been the centre of controversy over statements she allegedly made concerning the 2013 Tbilisi anti-homophobia rally protests, in which a small gay rights rally in Tbilisi was attacked by thousands of anti-gay protesters, led by priests, causing over 20 injuries. Following this incident, Iveri allegedly posted on her Facebook page a letter to Georgian President Giorgi Margvelashvili which said (in Georgian): "I was quite proud of the fact how Georgian society spat at the parade... Often, in certain cases, it is necessary to break jaws in order to be appreciated as a nation in the future, and to be taken into account seriously. Please, stop vigorous attempts to bring West's 'fecal masses' in the mentality of the people by means of propaganda."
Following the appearance of this letter, the Georgian gay rights organisation Identoba wrote to the Paris Opera demanding that Iveri's upcoming concert be cancelled. Their letter said: "We would like to bring your attention to homophobic and hate inspiring activity by one of your opera singers, Ms Tamar Iveri, resulting in death threats and physical injuries to many Georgians." Iveri then apologised, but did not at that time deny authorship of the letter.
In June 2014, controversy broke out again while Iveri was in Sydney rehearsing Otello with Opera Australia. She then denied having written the letter, blaming her husband. After several days of intense criticism, Opera Australia announced on 23 June that it had "released" Iveri from her contract. Also the Théâtre Royal de la Monnaie in Brussels dropped her from its future production of Un ballo in maschera in 2015.
- "Tamar Iveri". Opera Australia. Retrieved 27 June 2014.
- Tan, Sylvia (22 June 2014). "Opera singer calls gay people 'fecal masses' in homophobic rant encouraging violence". Gay Star News. Retrieved 27 June 2014.
- Koziol, Michael (21 June 2014). "Opera singer accused of homophobia blames husband". The Sydney Morning Herald. Retrieved 27 June 2014.
- Collins, Antonette (23 June 2014). "Soprano Tamar Iveri terminated from Opera Australia production Otello over homophobic comments". Australian Broadcasting Corporation. Retrieved 27 June 2014.
- Debbie Cuthbertson (June 23, 2014). "Opera Australia sacks soprano Tamar Iveri over gay slurs". The Sydney Morning Herald. Fairfax Media. Retrieved 25 June 2014.