Mrkonjić was born in Belgrade on May 23, 1942, and graduated in 1971 from the Faculty of Civil Engineering in Belgrade.
After graduating from the faculty, he worked in the Bureau for Studies and Design of Railways, and from 1974 he was the head of the Design Department. In 1977, he got a job at the Center for Research and Design, and with his merger with the Traffic Institute, he became its director.
He has participated in numerous projects in Algeria, Venezuela, Iraq, Kuwait, China, Gabon, Libya.
He was the leader of the renewal of Serbia in front of the Government of Serbia after the NATO bombing in 1999.
He has also been the Vice President of the National Assembly of the Republic of Serbia since May 8, 2007. After the President of the Assembly Tomislav Nikolić resigned, Mrkonjić took over the presidency of the Assembly sessions as the oldest of the Vice Presidents, until the election of the new President Oliver Dulić on May 23, 2007. The Government of the Republic of Serbia was sworn in on May 15, 2007.
Hello! came into possession of photographs of Milutin Mrkonjić from childhood. In one photo, she is with her sister Nada in her mother’s arms.