| 1920 | The College of Science was established; the school also opened a two-year commercial course. |
| 1921 | The school moved to a more spacious property and a new building on 2401 Taft Avenue, Manila with some 425 boys (some of them in high school) and with Br. Albinus Peter FSC as the grade school principal. |
| 1922 | The first commerce students graduated. |
| The first public debate of the school’s Debating Club under Brother Felix FSC was held. | |
| 1923 | Br. Acisclus Michael FSC was named DLSC President. He would serve the post until 1927. |
| Military drill was given for the first time to boys in the fourth grade and up. | |
| 1924 | In August, the maiden issue of the student publication Green & White was released. |
| The St. La Salle Hall was completed. | |
| De La Salle College was recognized as one of the best private schools in the country by the Board of Educational Survey created by the Philippine Legislature. The board was tasked to make a study of education and all the educational institutions, facilities, and agencies in the country. | |
1927 |
Br. Celba John FSC was named DLSC President, a post he would serve until 1930. He also pushed for the creation of the National Collegiate Athletic Association (NCAA) to promote sports among Catholic school institutions. He is considered the “Father of Collegiate Basketball.” |
| 1928 | Br. Basilian FSC was appointed Sub-Director in lieu of Br. Albinus Peter FSC, who sailed on the Oldenburg for the Penang Novitiate. |