This study examined how student characteristics and secondary education backgrounds influence the academic performance of first-year Bachelor of Science students in Computer Science at the Kandy Regional Centre of the Open University of Sri Lanka (OUSL). Using a deductive approach, a random sample of 110 students was selected from a population of 183, and data was collected through a self-administered questionnaire. The findings indicated no significant difference in performance in Level 3 Computer Science courses between male and female students. Similarly, there was no significant difference in grades between students who had passed the General Certificate of Education (Advanced Level) in the Bio-Science and Physical-Science streams. Additionally, unemployed and unmarried students performed better than employed and married students. Crucially, the study found that proficiency in English is essential for success in Computer Science courses at the university level. This study had some limitations. First, it was conducted at a single regional center within OUSL, limiting the generalizability of the findings and future research should include all regional and study centers to obtain a larger, more representative sample. Second, since this study relied solely on a quantitative survey, a mixed-methods approach in future research could provide deeper insights into students' perceived challenges with English proficiency. Finally, more advanced statistical analyses could be used to establish causal relationships between relevant factors. It is recommended that, prior to beginning their undergraduate programs, students receive targeted language training, as language barriers may limit the academic performance of students with limited English proficiency.