<p>Internationally, scientific literacy is a major goal of science education in the twenty first century. In Tanzania, where there is a widespread lack of public understanding about major health issues, biological literacy is needed so that people can make decisions about the socio-scientific issues that confront them. To that end, the Tanzanian school curriculum aims to connect students’ understandings of Biology to their everyday lives but few studies have been conducted that show whether these aims have been achieved, especially in junior secondary school. This ethnographic case study investigates the ways in which the junior secondary school Biology curriculum in Tanzania supports or constrains the development of biological literacy and how institutional context, particularly as it relates to urban and rural schools, influences the delivery of the Biology curriculum. Teachers’ and Year Four students’ of secondary schools views about school Biology were sought in the course of this study and the issues that emerged were analysed using social constructivist and social constructionist theoretical frameworks. Data were collected through student questionnaires, student focus group interviews, teacher interviews, and classroom observations. The research sites included rural and urban schools, and government and private schools. The findings suggest that the Biology curriculum and the ways it is delivered do not adequately address the students’ needs and therefore is unlikely to enable them to become biologically literate. Rural schools are less well equipped than urban schools to deliver the curriculum and teachers and students face bigger challenges. A key finding was that Tanzanian young people have a strong desire to learn more about reproductive Biology and health issues but these are not prioritised in the current curriculum. In light of these findings, curriculum changes are recommended to provide learning opportunities for students to gain biological knowledge and skills that are relevant to their daily lives.</p>