This study examined the nature of quality assurance frameworks in science education and the factors negatively affecting the quality of science education in the Johannesburg South district. The study explored the quality assurance practices, challenges that impede the attainment of quality science education in schools and the impact of quality assurance on the quality of science education. The Integrated Quality Management System, which encompasses whole-school evaluation, is the main policy used in secondary schools’ quality assurance system. A mixed methodology design was used in the research. The data collected was both qualitative and quantitative and was obtained from both primary and secondary sources. The qualitative data provided research opportunities which extended the type of information collected. It implied an interpretive or subjective approach with the focus being on how the respondents experienced and understood the quality assurance processes. Concurrent triangulation designs or convergent parallel design was used in order to develop a complete understanding of the research problem by obtaining different but complementary data for validation purposes and enhancing triangulation. Quantitative and qualitative data was collected at the same time and the findings were integrated in order to understand deeper the quality assurance mechanisms applied in science education. The use of multiple perspectives, theories and research methods resulted in rich information being gathered for analysis. The study revealed that quality assurance practices, ranging from Integrated Quality Management System, Whole-school Evaluation and Assessment Quality Assurance among others, had a positive influence on the quality of science education. The results indicated that quality assurance policies and mechanisms present were followed by schools and the district support helped to improve the quality of science education. The presence of quality assurance policies and mechanisms had a positive bearing on the quality of science education. The lack of infrastructural resources, non-availability of laboratory technicians, science educator work overload, parents’ non-involvement in academic support, poor learner subject selection criteria and non-rigorous quality assurance follow-up mechanisms were the main factors hindering the quality of science education. / Educational Studies / D. Phil. (Education)