De la Salle, an innovator in the field of education, was canonised by the Catholic Church on 24 May 1900, and in 1950 Pope Pius XII declared him to be the Patron Saint of teachers.

As required by the Diocese of Lafayette, the school operates a non-discrimination policy in regards to race, gender or religion in the areas of admission, academics, athletics and extracurricular activities.

After Catholic High became co-educational, the enrolment surged from around 350 to almost 950 in one year; this was due, not only to the (roughly 250) girls from Mount Carmel, but also to an influx of over 300 students from state schools.

Once the campus additions had been completed in 1992, the school's chaplain sought to have the well-known statue of Our Lady of Mount Carmel transferred to De La Salle Drive, but the Sisters declined.

Unfortunately, during that same year Hurricane Andrew caused one of the large oak trees on Mount Carmel's campus to collapse, destroying the statue.

In the 1990s, due to a fall in vocations, the Brothers of the Christian Schools found it necessary to end their time at Catholic High after serving the New Iberia community for many years.

The motto of the school is "Acta non Verba" which means "Actions not Words", and this was the driving force behind the decision in the 1980s to reach out to the most needy members of the wider community.

Catholic High also established a reputation for excellence in the areas of science and mathematics, with its well-attended annual fairs, organised and directed by long-serving faculty member, Dr. Donald Voorhies.

[7] The LaSallian tradition, which reaches as far back as the 17th century, means that Catholic High is called to strive to help students grow in faith through prayer, active participation in their place of worship, together with involvement in the wider community through service to others, particularly to those people most in need.

In the minds of the Brothers "For Lasallian establishments to be the living expression of the Good News, they must be places for dialogue in truth, freedom, and hope."

[8] Therefore, the mission which Catholic High embraces is to educate the whole person, challenging each student to reach his/her fullest potential as a well-round individual who is intellectually competent, open to growth, religious/spiritual, loving, and committed to doing justice through generous service to the People of God.

Even after the leaving of the Brothers, the dramatic enrolment increase of late the 1980s was maintained, with a student population between 950-975 and the school continued the expansion of its campus under its first lay principal, Mr. Dave Cavalier.

During his tenure, the library was converted into a chapel (containing stained glass windows depicting the school's history) enabling the celebration of the Eucharist to be held for class groups.

Charles Langlois, published a letter in the Daily Iberian newspaper which stated that: "The 70 person turnover in personnel was discussed as well as other issues."

Adding to the school's already strong academic programs were the addition of dual enrollment courses for juniors and seniors in both English and Social Studies.