Studies have indicated that nutrition plays a crucial role in cognitive development among school-aged children. In Tanzania, where many schools are situated in low-income areas with limited resources, the impact of school-based nutrition programmes on students' cognitive performance remains underexplored. The mixed methods design incorporates both quantitative and qualitative data collection techniques to provide a comprehensive view of the impact of nutrition programmes. Quantitative data will be collected through standardised cognitive tests administered to students in participating schools, while qualitative insights will be gathered via interviews with teachers and parents. Findings suggest that school-based nutrition programmes have led to significant improvements in students' test scores, particularly in reading comprehension and arithmetic skills. Interviews revealed positive perceptions of the programmes among educators and guardians, attributing their success to enhanced concentration levels and improved health. The mixed methods study provides valuable evidence on the efficacy of targeted nutrition interventions in enhancing cognitive performance among Tanzanian school children. The research underscores the importance of integrating nutritional support into educational settings for promoting overall student well-being. Based on the findings, it is recommended that policymakers consider expanding and funding such programmes to benefit a broader population of students across Tanzania. Additionally, ongoing monitoring and evaluation should be conducted to ensure continuous improvement and sustainability. nutrition programmes, cognitive performance, Tanzanian schools, mixed methods study