The USC BOYS SCHOOL traces its history from the free primary school opened in 1595 in the Parian by Spanish Jesuit missionaries, Father Antonio Sedeño, Father Pedro Chirino, and Father Antonio Pereira. After sufficient endowment, the school was named the Colegio de San Ildefonso in 1606. The colegio was moved to the wooden buildings in Martires Street in 1725 and it was housed there until 1769 when the Jesuits were expelled from the Philippines. It was re-opened by Bishop Mateo Joaquin de Arevalo with secular priests in charge in 1783. The same building was used but the name was changed to real Seminario de San Carlos. From a primary school to grammar school, the colegio now became a school for those who wanted to join the religious life. The Dominican Fathers took over the school management from the Diocese in 1852. Then the Vincentians came to the Seminario-Colegio de San Carlos in 1867. Externos or students who lived outside and had no intention to become priests were accepted. In 1891 college-level courses were offered and in 1908 authority to confer bachelor’s degree was granted. Then in 1924, the Vincentian fathers segregated students for priesthood from the high school and college students. By virtue of a papal decree the seminary became a separate entity. Both groups continued to use the Martires school site. In 1927, only the high school department remained together with the Seminary.
In 1935, the administration of the school was turned over to the Society of the Divine Word (SVD – Societas Verbi Divini). Although college courses were opened in 1934 and women admitted in 1940, the high school department remained exclusively for boys. On December 8, 1941, classes were interrupted by World War II until August 1, 1945 when classes on both levels were reopened. The enrollment of the high school department swelled in 1947-1948. A new high school building was constructed at the corner of P. del Rosario and Pelaez streets for the growing population. At this time, the high school organized evening classes which were co-educational. However, with the expansion of the new University of San Carlos, the Boys High school was moved to its present site at General Maxilom Avenue in 1955. The night school was phased out in 1957.
The Elementary Department of the Boys School was established to accommodate male pupils from the Colegio de la Inmaculada Concepcion and St. Theresa’s College which had to phase out their intermediate classes for boys. The elementary department started with Grades V and VI during the school year 1959-1960. In school year 1966-1967, Grade IV pupils were admitted. One grade level after another was added in the following years thereon, until school year 1969-1970 when Grade I pupils were accepted. Complete elementary education was finally offered by the Boys School. In school year 1980-1981, the school opened classes for Kindergarten.
Both the Boys High School and the Boys Grade School are accredited school. The Philippine Accrediting Association of Schools, Colleges and Universities granted accredited status to Boys High School in 1985 and to Boys Grade School in 1988.
In 2005, the Boys Grade School becomes co-educational. It accepted girls in Kindergarten 1 and 2, and in Grade 1 to Grade 5. The Boys High School accepted the first female students in the first year level. With this new development, the school was renamed the University of San Carlos, Basic Education Department, North Campus. This school year 2009-2010, all grade school and high school levels are completely co-educational.