On the foundation stone was laid by John M. Njuguna, then District Education Officer(D.E.O), Nyandarua District. The school was named Ngano Secondary School after the Ngano sub-location, which is located in the Gathanji Sub-County of Nyandarua County. The school is located along the Kalro-Charagita road, approximately 1.5km from Gathanji town.
The school was started by the local community, with the assistance of the then District Education Officer, Mr. J. M. Njuguna, and the first headteacher, Mr. J. K. Mwangi. The school was initially established as a day school offering the 8-4-4 curriculum. Slowly but surely, the school has grown in both size and reputation, attracting students from the surrounding areas, producing notable alumni who have excelled in various fields.
On January boarding section for both boys and girls was introduced with an initial enrolment of 42 students, a population which has since grown to 100+ students. The introduction of the boarding section has greatly enriched the school's learning environment, allowing for more focused study and extracurricular activities.
Ngano Secondary School has continued to grow and adapt to the changing educational landscape. In the new CBE curriculum, the school is a cluster 4 institution, offering a wide range of subjects and programs to meet the diverse needs of its students. The school is committed to providing a holistic education that not only focuses on academic excellence but also promotes character development, leadership skills, and social responsibility among its students.