Due to the unprecedented increase of enrollment in San Pablo City National High School, it could no longer accommodate all the students coming from eight barangays of San Pablo. This problem was solved through the assistance of the city mayor, Hon. Vicente B. Amante & other local officials. Schools were brought by the local government to the barrios. Apprehended to this, through the Sanguniang Barangay of Stmo. Rosario headed by the late Chairman Elias Corales, the site, the owner of the land real-property was donated to the city Government pursuant to the Kapasyahan Blg. 93-3 dated July 1, 1993 citing the need for the construction of a barangay high school which can be effected through the support primarily of the city government. This school foundation & establishment started the first school construction of a three-classroom one storey building in a one hectare government lot.
Stmo. Rosario Annex together with the four annexes (1). Del Remedio Annex, (2). Dolores, (3). Sto. Angel, & (4). Annex V started to operate in the school year 1995-1996 to unload the burden of parents concerning the transportation expenses.
SY 1995-1996, four pioneer teachers were assigned in Stmo. Rosario Annex. They were Mr. Ronie Nacario who was designated as Teacher-in-Charge, Mrs. Teresa Yema, Miss Maritess Fandiño and Miss Michelle D. Benedictos. The following year on January 1996, Mrs. Editha L. Fule became one of the initial teaching forces of Stmo. Rosario High School With Mr. Ricardo T. Manalo as principal of the City High main and its annexes.
The same year, June 1996 to be exact, a two-room building was constructed since enrolment increased due to an additional year level. Another building was raised the year after, it was donated by the Lions Club of San Pablo City, Progressively, as supported by the General Parents Teachers Association of the consecutive batches, Mr. Pruden Esturas as PTA President 1995-1999, Mr. Melvin Cuenca 2000-2002 and Ret. Col Roberto Cuasay 2003 to present, five more classrooms were added, number of teachers were also increased from four to sixteen.The following are names of teachers according to dates they were in. Lorelie Caringal Mission, Renante M. Bonilla, Analyn N. Nacario, Rafaela M. Sarmiento, Noreen C. Aviñante, Gina C. Valencia, Perlita V. Delos Angeles, Annaliza Ampong, Gemma Mediana, Rubelyn N. Enero, Sarah J. Sario, Jun Pornobe who were once loaned from elementary department.
Unfortunately, due to the continuous increase of jeepney fare some teachers were voluntarily transferred to other schools near their homes. For that, another sets of teachers were assigned to the school, Nancy Sudario, Maritess Matuto, Jennefer Sesgundo Dimaranan, Rechel A. Rivera, Laila Hermosa Pere Godoy, Sherwin Belen, Krishen Labrado, Mercedes Prudenciamo, Imelda Mendoza, Laarni Zacarias, Rudy Gonzales, Benedict Rapsing & Liezel L. Katigbak.
Mr. Manalo as principal of the school city high main & its five annexes nurtured & guided the students & teachers in all academic & extra-curricular activities. All school affairs headed, from him downward to remote annexes, dissimilated through teachers-in-charge/ teacher leaders to teachers. Consequently, by this school annexes system, the Stmo. Rosario had the pride with its concrete proofs of excellence. The school became an agent of academic & sports excellence linking the barrio students to division, regional & even national competitions bringing home the prizes, medals, plaques & trophies. These are all exhibited at the school administrative office. On matters of school administration & education supervision, Mr. Manalo appointed subject area department heads for the annexes’ assistance. In Stmo. Rosario Annex, they were , Mrs. Aurora Cornelia (Science), & then Mrs. Helen Ramos (Science).