This study focused on investigating the performance of a private high school graduating students in the yearly conducted National Career Assessment Examination given by the Department of Education. The researchers would like to know if the present curriculum content used by a private high school is in line with the national standard. To serve this purpose, the NCAE results of a private high school for two school years were gathered and recorded. Then their academic performances in Mathematics, Science and English (base on final grade) were noted. T-test was used to see if there is a significant difference between these two factors. It was found out that the mean percentile rank of a private high school students in Science for the past two years was 67.05 with a standard deviation of 21.90. In Mathematical Ability , their mean percentile rank was 79.23 with a standard deviation of 16.51. And the mean percentile rank for English was 79.80 with a standard deviation of 18.48. On the other hand, the mean academic performance in Science was 85.50 with a standard deviation of 4.80. In Mathematics, the mean academic performance was 85.41 with a standard deviation of 5.64. And in English, their mean academic performance was 84.00 with a standard deviation of 4.64. Using t-test, it was concluded that there is no significant difference between the result in NCAE and the students? academic performance. Base on these findings and conclusion, recommendations directed to specific persons were laid down, and future researchers were encouraged to replicate the study for the future graduating students of a private high school.