<p>Improving quality science education (SE) in many countries across the world has been a focus of international inquiry. Though Tanzania, like many other countries, has placed an increasing focus on improving the quality of SE experiences in its schools, little has been made to achieve this goal. This means the process of providing quality SE remains problematic and challenging. This study explores promising practices for improving the quality of SE in Tanzanian junior secondary schools (JSS) from the perspectives of 67 key SE stakeholders involving: educators, policy makers, parents, students, science alumni and selected education officers. In order to address the issue, the study used a mixed method approach involving interviews and questionnaires (with all respondents except students); document review, and focus group discussions (with students). A pragmatic perspective, with an emphasis on creating a more relevant, contextual, responsive and functional SE experiences in schools, was used as a lens. The study was conducted in two concurrent (embedded) phases within two regions in Tanzania beginning with in-depth interviews with policy makers and followed by intensive study of schools. All phases of data collection generated qualitative and quantitative data sets, which were then analysed using thematic analysis and descriptive statistics respectively. The findings of this research identified that despite policy articulation, the understanding and delivery of quality SE in Tanzanian JSS has remained debatable, divisive and antagonistic controversy over its meaning, value, nature, features and measures. As such, a comprehensive framework is needed to harmonise the existing and diverse conceptions of what quality SE is among different stakeholders. The findings also revealed that there are several contextual challenges rooted in the processes of planning, delivery, assessment and monitoring of quality SE practices in schools. Respondents identified these challenges as limiting the efforts to provide quality SE. Employing comprehensive and multiple frameworks to address the issue of quality SE is likely to help in making school SE experiences become as relevant, context responsive and functional as possible. This thesis hybridises an American pragmatism and uses it in linking and integrating collective and different perspectives towards identifying promising practices for quality SE in Tanzanian JSS.</p>