Kogarah High School has a long history of student achievement both academically, and on the sporting field.

The expansion of the railway line to Kogarah and beyond, early in the 1880s was a great influence on Kogarah High School as it enabled easy travel for students from neighbouring suburbs and enrolments subsequently increased.

Here is an architect's description of the building contained in Department of Education records: "The building is of Jacobean type, built of buff bricks, with dark brick and stone dressings and roofed with red Marseilles tiles."

The school continued to expand in the first decade of the 20th century, reaching an enrolment of 1,500 in 1909.

This meant that they both were teaching students up to the level of the Leaving Certificate.