Nairobi Technical Training Institute derives its history as far back to the year 1951 when it started as “Modern High School” catering predominantly for the Asian community residing in the neighborhood. Though a secondary school, the curriculum offered at the time had a bias towards the inculcation of vocational skills which encompassed Mechanical Engineering and Carpentry & Joinery. In 1953, the name of the school was changed to Technical High School and the Cambridge School Certificate Examination was first taken in 1954.

At independence and in the spirit of the Ominde Education Commission of 1964, the school opened its doors to all races. The curriculum continued to lay emphasis on Technical Education and was expanded to include Plant Mechanical, Woodwork, Electrical and Motor Vehicle mechanics skills. Both ‘O’ and ‘A’ level classes were accommodated.