Mr. Gachukia, a self-made entrepreneur, started his career as a Secondary School teacher after graduating with a Diploma in Education from Makerere University College in 1956. Upon graduation, Mr. Gachukia taught in various Secondary Schools in both Kenya and Uganda including, Kagumo High School and Thika High School.
He thereafter studied Diplomacy in France between 1962- 1963. From 1963 to 1974 he worked with the Ministry of Foreign Affairs as the Charge d’affaires at the Kenya Embassy in Paris and later as the Chief of Protocol until he retired from Civil Service.
In 1974, Mr. Daniel Gachukia retired from Civil Service to join the Board of Directors of East Africa Industries Ltd and later retired in 1989, to launch the Riara Group of Schools. For five years he was Chairman of the Board of Governors of Thika High School.