Mr. Gahukia is a self-made entrepreneur who started his career as a Secondary School teacher after graduating with a Diploma in Education from Makerere University College in 1956.On graduation Mr. Gachukia taught in various Secondary Schools in Kenya and Uganda including, Kagumo High School and Thika High School. He studied Diplomacy in France in 1962- 1963. Between 1963 and 1974 he worked with the Ministry of Foreign Affairs as the Charge d’Affairs at the Kenya Embassy in Paris and then as Chief of Protocol until he retired from the civil service.

In 1974 he retired from the Civil Service to join the Board of Directors of East Africa Industries Ltd. In 1989 Mr. Gachukia retired from East Africa Industries to launch the Riara Group of Schools. For five years he was Chairman of the Board of Governors of Thika High School. He also served for six years as a member of the Kenyatta University Council and Chairman of the Council for 3 Years. He is a Life Governor of the Agricultural Society of Kenya and was for 3 years the Chairman of the Nairobi International Show.In 1994 Mr. Gachukia played a leading role in the establishment of the Kenya private Schools’ Association (KPSA) for which he was founding Chairman for 10 years and is now the Patron. This is an association of owners of private schools in Kenya, which follow the Kenya Curriculum of Education.