A major portion of the student body reside in Rockville Centre, and neighboring towns.

The school resides on campus along with St. Agnes Cathedral, the base of the Diocese of Rockville Centre.

The increasing need for Catholic elementary education in Rockville Centre made the school soon outgrow their ten-room building.

This led to the purchase of the Clinton Avenue building from the Rockville Centre Public School District in 1957.

[3] The scores of St. Agnes students to local public districts as well as fellow Diocese of Rockville Centre schools are comparatively higher.