He was the second official spokesman for the government of Kenya, a post he was appointed to by the president of Kenya on 22 November 2012 and held until 8 August 2013 when the office was dissolved.
Muthui Kariuki holds a degree in B.Education(Hons) from Kenyatta University,Post Graduate Diploma in Mass Communication from University of Nairobi and a master's degree in Communication from University of Nairobi.