Abstract: This study examined the impact of school quality assurance practices on students’ academic performance in public secondary schools in Mafia District Council. The study was guided by two research objectives, namely to: identify strategies used by SQA to assess the school services on students’ academic performance in public secondary schools; examine the challenges facing SQA during quality assurance exercises on students’ academic performance in public secondary schools. This research employed a mixed-methods approach with a convergent parallel design. The study utilized questionnaire and interview methods for data collection. Quantitative data were analysed by using descriptive statistics with the aid of SPSS while qualitative data were analysed by using content analysis. The findings revealed that school quality assurance practices were significantly influencing students’ secondary school academic achievement. Furthermore, the strategies used by SQA to assess the school’s services were significantly and highly correlated with students’ academic performance. The study highlights the challenges facing SQA during quality assurance exercises, including inadequate facilities and a lack of teachers implementing SQA recommendations. It is recommended that the government increases budget for provision of SQA facilities providing regular training and seminars through in-service training programs in order to accommodate policy and technological changes.