Originally the high school was part of the primary school, however children were often required to travel to Dubbo or boarding school for their secondary education.

Narromine High School teacher Cathy Reynolds, who has been at the school for 15 years, said much has changed over the years.

"A lot's happened in that time," she said.

"It was set up in response to people in Narromine who wanted their kids to go to school here, and there was more and more of a need for secondary school so they eventually got the agreement and the funds to set it up and it's gone on from there."

An application for a public school at Narromine was originally made in December 1882, however was rejected by the Department of Education because the average attendance would have been below 20 students. Yet the school was granted as a provisional school.

The provisional school opened in April 1893 with James Townsend, a 17-year-old teacher. By the end of 1883, enrolments had increased to 46 and the school was raised to public school status.

As early as 1958 the Narromine Shire Council had requested that a full high school be established as sixty secondary students were travelling daily to Dubbo, and others were boarding there.

In 1963 approval was given for Fourth Form classes and with increasing enrolments a separate secondary department was established in 1966.

In 1968 when enrolments were approximately 300, the Minister for Education approved the establishment of a separate high school from the beginning of 1969, headed by principal Mr Gallagher.

Technical faults in the new three storey high school block (the present 'B' block) delayed the official opening.

However the school was officially opened on September 8, 1970 when Minister for Education and Science Charles Cutler unveiled plaques at Narromine High and Narromine Public School.

From this time both schools have developed separately but cooperatively.

To celebrate the milestone the school are hosting an open day on Saturday, September 5 from 10am to 12pm.

There will be morning tea, open classrooms and history displays.

There will also be a planting of a weeping crab apple tree to mark the occasion and a plaque erected.