After establishment of the Azerbaijan Democratic Republic on May 28, 1918 Amirjanov was involved in political life of the country. On June 17, 1918, when the second cabinet of Azerbaijan Democratic Republic convened, Amirjanov was appointed Minister of Finance and served in the position until October 6, when the cabinet went through reshuffling and he was appointed State Controller. He held the office until December 7, 1918. Elected to the Azerbaijani parliament as an independent deputy, Amirjanov was a member of the finance-budgetary and census commissions. In order to enhance trade relations with other countries, he co-founded "Dəyanət" company. During Turkish Army of Islam's march on Baku in September 1918, Amirjanov along with Behbudkhan Javanshir were in the frontlines when Ələt was taken.