He has dropped his long career in the public sector for State House
He is a politician who once served as a Minister of Cooperative Development and Marketing in Kenya's grand coalition government (2007-2013).
Nyagah was a member of the then governing Kenya African National Union and a minister in President Daniel Arap Moi's office until quitting both the ministry and the party in the run-up to the 2002 general election. He fought the election in Gachoka Constituency as an opposition National Rainbow Coalition candidate.
He was a member of Orange Democratic Movement's 'Pentagon' in the lead up to the 2007 general election. He studied Bachelor in Economics and Political Science at the University of Nairobi (1970). He also holds a Masters degree in Management (Finance and Management option) from Northwestern University, Evanston, and Chicago, Illinois, USA.
He later worked with The First National Bank of Chicago, under its First Scholar Program. Some of the places he worked were; Kenya Bus Service, Murdock, McRae and Smith Accountants and British American Tobacco Kenya Limited.
He also worked as a banker for 10 years (1973-1983). During this period, Hon Nyaga worked with The First National Bank of Chicago (part of today’s JP Morgan and Chase Bank, New York). He is the chancellor of the Cooperative University of Kenya.