In 1970, Njoroge assumed the role of Kenyan High Commissioner to the United Kingdom, a position he held until 1979.
[4] The elder Njoroge worked as a cook at a Presbyterian mission in Nairobi and later opened a store[1] and a transport company.
[1][5] Njoroge attended Alliance High School in Kikuyu, Kenya and Busoga University in Iganga, Uganda before moving to the United States where he attended Central State College in Wilberforce, Ohio and then in 1960 he went to Boston University[6] where he received a M.S.
[8] After the ascension of his cousin, Jomo Kenyatta, to the presidency, Njoroge held a number of positions in his government.
He was named assistant secretary, Ministry of Lands and Settlements (1963–1964); senior assistant secretary, Ministry of Foreign Affairs (1964); delegate to the Organisation of African Unity (1964); member of the Delegation to the Commonwealth Heads of Government Meeting (1964); member of the Kenyan Delegation to the United Nations General Assembly (1964, 1965, 1966); head of the Africa and Middle East Division of the Ministry of Foreign Affairs in Nairobi (1964–1967); counselor of the Kenyan Embassy in Bonn, Germany (1968–1970); Ambassador to Italy and Switzerland (1974); and Kenyan High Commissioner to the United Kingdom (1970–1978).