He was the Governor of the Central Bank of Iran, appointed on 2 September 2008. His term as the Governor was ended on 2 September 2013 and he succeeded by Valiollah Seif. President Mahmoud Ahmadinejad appointed Bahmani to this position in September 2008 after dismissing then-Governor Tahmasb Mazaheri.
Mazaheri had served in his office for about one year.
The changeover took place shortly after a decision by the Central Bank of Iran to raise the interest rate on deposits, which was intended to the accelerating inflation rate. There was tension between government officials who favored an expansionary monetary policy despite the inflation and bankers who sought to contain lieutenant
Gholamreza Mesbahi-Moghadam, a key figure in the Majlis" Economic Commission, opposed Bahmani"s appointment and the past dismissal of Mazaheri, saying "he change of the China, Burma, India Theatre of Operations was not desirable and I believe this change should have not taken place". On 28 February 2009, Bahmani vocally criticized other financial institutions for the large injections into their currency supplies to fight the global economic recession.
He said, "the United States of America and some major European countries, they ratified economic stimulus packages and injected thousands of billions of dollars into their economies that would increase inflation in the world in the near future".
He also asked the International Monetary Fund and World Bank to give more support to developing countries. In the International Monetary Fund Spring Meeting from April 25–26 in Washington, District of Columbia, Bahmani served as the representative of the group of 24 developing countries, which is known as "G-24". In his term, Bahmani came up with differing estimates of inflation compared to Ahmadinejad, with the former giving 14 percent and the latter 25.4 percent from 2007-2008.