To qualify, an applicant must have
- obtained at least 80% average on his/her Grade 6 1st grading period as shown in his/her Form 138-A (Report Card) or certified by the class adviser.
- passed the entrance examination administered by the CLSU Science High School.
Every year, an average of 400 applicants take the entrance examination, which is usually held during January or February. Only the top 80 examinees and the top 10 addendum whose applications for enrollment have been approved will be accepted as freshmen. Addendum are identified children of CLSU faculty and staff.