In response to international concerns about scientific literacy and students' waning interest in school science, this study investigated the effects of a science-writing project about the socioscientific issue (SSI) of biosecurity on the development of students' scientific literacy. Students generated two "BioStories" each that merged scientific information with the narrative storylines in the project. The study was conducted in two phases. In the exploratory phase, a qualitative case study of a sixth-grade class involving classroom observations and interviews informed the design of the second, confirmatory phase of the study, which was conducted at a different school. This phase involved a mixed methods approach featuring a quasi-experimental design with two classes of Australian middle school students (i.e., sixth grade, 11 years of age, n = 55). The results support the argument that writing the sequence of stories helped the students become more familiar with biosecurity issues, develop a deeper understanding of related biological concepts, and improve their interest in science. On the basis of these findings, teachers should be encouraged to engage their students in the practice of writing about SSI in a way that integrates scientific information into narrative storylines. Extending the practice to older students and exploring additional issues related to writing about SSI are recommended for further research. (Contains 1 note, 3 tables and 2 figures.)