This study explores students' perceptions of the effectiveness of the Integrated Science School-Based Assessment (SBA) within the Caribbean Secondary Education Certificate (CSEC) framework. Grounded in educational theories that support continuous assessment, the SBA aims to foster critical thinking, practical application, and independent learning through hands-on experiments and collaborative projects. Despite these intended benefits, limited empirical evidence exists on how students perceive the SBA’s role in enhancing academic performance, particularly with regard to gender differences. This research addresses this gap by examining how students view the contribution of the Integrated Science SBA to their CSEC performance and whether perceptions differ between male and female students. A quantitative research design was employed, utilizing a structured 20-item Likert-scale questionnaire administered to a stratified random sample of thirty-five (35) Integrated Science students from a secondary school. The instrument demonstrated high internal consistency (Cronbach's alpha = 0.81). Descriptive statistics showed generally positive perceptions of the SBA, with students agreeing that the SBA enhances understanding of scientific concepts, critical thinking, and exam readiness. However, areas of concern included clarity of instructions and adequacy of teacher support. Independent samples t-tests revealed no statistically significant differences between male and female students' perceptions across all questionnaire items, indicating a shared consensus on the SBA’s effectiveness regardless of gender. These findings support the conclusion that the Integrated Science SBA positively impacts students’ academic experiences and outcomes in a gender-neutral manner. Despite its small sample size and context-specific focus, the study provides valuable insights for educators and policymakers. It recommends clearer guidance, enhanced teacher support, extended task timelines, and increased opportunities for collaborative learning. Addressing identified concerns could further strengthen the SBA’s role as a meaningful component of the Integrated Science curriculum.