Immaculata High School opened in 1956 as a part of Immaculate Conception Parish.

Located in the Roman Catholic Archdiocese of New Orleans, the School Sisters of Notre Dame served Immaculata from its inception until May 1979.

At the time, however, the absence of a boys' Catholic High School in the area prompted parents to seek admission also for their sons.

[2] On September 10, 1956, Immaculata High School opened its doors to 50 freshmen.

One group of concerned parents, students, and alumni created a website called Stop The Merger to pass along information in the hope of preventing the merge of Archbishop Blenk and Immaculata.