This work showed how alumni involvement can be used as an important indicator of quality curriculum. The researchers used the output for the curriculum enhancement of the secondary Education of Colegio de San Juan de Letran Calamba (Colegio). Using survey-questionnaires to the High School (HS) graduates of academic year 2012- 2013, the 60 alumni-respondents were asked of: 1. their demographic profile; 2. how efficiently the Colegio trained them under four areas of the 21st century competency skills; 3. Their evaluation of the change in emphasis of their undergraduate training they received from the school; and, 4. their rating of how much the school prepared them for their tertiary education and experience. In consonance with the descriptive nature and design of the study, descriptive statistics was applied to summarize the data. Results showed that the respondents manifested more than adequately the 21st century skills that enable them to face college life. It was recommended that a regular curriculum review should be done with the active participation of the alumni, parents, and teachers to ensure that the curriculum is aligned to the glocal needs. And, to ensure the accurate assessment of the students’ 21st century skills, further research should incorporate multiple measures to permit triangulation of inferences.