In 1976, the high school glee club's female voices conducted by Ms. Celia Yu Ong, became the national champion in the Himig ng Lahi choral competition, a feat made more significant because they bested all of the other regional champions and aspirants. They had hurdled the qualifying rounds, both the district and regional finals, and went on to the National Finals as the only Chinese school represented. In the same year, the school became a Filipino school as mandated by the 1973 Philippine Constitution requiring Filipinization of all Chinese schools. The Chinese class hours were subsequently reduced.
The decrepit Mosher Hall building on the high school campus was demolished in 1980. A five-storey annex building on its site was completed in 1982. Twenty-one sets of computers set the school off into the age of advanced technology as the first computer class was held in 1985.
In 1987, the high school department attained the singular honor of being the first Chinese-Filipino school to be conferred the Accredited Status by the Federation of Accreditation Agencies of the Philippines (FAAP), through the Association of Christian Schools and Colleges Accrediting Agency (ACSC-AAI) which was duly recognized by the Department of Education. The enrollment was now 4,000 in number. In 1990, the next phase of accreditation procedure yielded the best results as both the elementary and pre-school departments followed suit in attaining accredited status.
The St. Stephen's Learning Center was established in 1989, in cooperation with St. Stephen's Parish, as an outreach program giving free nursery lessons and Christian education to unschooled young children of the neighboring areas. Previously in 1984, the annual free clinic was organized as a mission program which also gave Christian counseling to the patients who came to be attended to for their medical needs. This was jointly carried out with the Alumni Association and the Parish.
In 1990, Dr. Tiu Uy Pei Suan succeeded Mr. Ong To Sieng as principal when the latter retired. Named assistant principals were Mrs. Joy Dy and Mrs. Judy Tan.