The Colegio, through the Community and Extension Services Department (CESD), has established 32 partnerships with the public and private sectors in the conduct of its community and extension programs, projects and activities.
Within the City of Calamba, the City Environment and Natural Resources Office (CENRO) is a partner of the School for environment and health advocacy projects. Another one is an educational institution, the Castor Alviar National High School, for the Be a Parent Project where poor but deserving students are given scholarship grants to help them continue with high school education.
Specific to extension projects of the Colegio, Brgy. Masili in the eastern portion of the City of Calamba has been chosen among the 54 barangays in the City of Calamba as partner community from 2015-2020. No less than the Rector and President of Letran Calamba, Rev. Fr. Honorato C. Castigador OP, together with several administrators, graced the occasion of the signing of the Memorandum of Understanding in July 15, 2015 in the said barangay.
Outside the City of Calamba, CESD has three partner municipalities and twenty two partner barangays for the Makipamuhay student immersion project mostly for second year students enrolled in the courses Society and Culture and Religious Education IV. The municipalities of Pakil, Pangil and Santa Maria in the 4th District of Laguna serve as partners for this project. In Pakil, the three partner barangays are Gonzales, Tavera and Banilan. There are six partner barangays in Pangil namely: Balian, San Jose, Isla, Galalan, Dambo and Mabato-Asufre. The municipality of Santa Maria accounts for twelve partner barangays namely: Cabuoan, Kayhakat, Cambuja, Bubucal, Tungkod, Inayapan, Calangay, Coralan, Bagumbayan, Parang ng Buho, Macasipac and Adia.
There are four partners for professional networks. Within Region 4A, CESD is part of the Network of CALABARZON Educational Institutions- Community Extension (NOCEI-Com Ex). In the national level, CESD represents the Colegio in three national community and extension-related organizations like the Philippine Association of Extension Program Implementors, Inc (PAEPI), Community Development Society of Philippines (CDSP), and community and extension offices of HEIs under the Dominican Province of the Philippines Incorporated (DPPI).