This paper evaluates the effectiveness of the semester and the credit programs of high school education in Kuwait in terms of their graduating students' preparedness for continued and successful academic performance in programs of higher education. Students' percentile graduation rank from high school and their performances in the English, math and chemistry aptitude tests conducted by Kuwait University's Admissions Office are included in the evaluation of program effectiveness. Findings indicated that the student graduates of the Semester System had a lower percentile rank compared to their credit system counterparts, when graduating from his schools. However, they outscored the graduates of the Credit System in the math and chemistry aptitude tests by a significant margin. The differences in the math and the chemistry test scores for the graduates of the two high school programs were statistically significant.