This study investigates the effects of a scientific literacy strategy which focuses on reading, writing, talking and doing science on the development of grade six and seven learners' general literacy skills, both in their home language (isiXhosa) and the language of classroom instruction (English). A mixed method design was used. Quantitative data were generated via baseline and post-testing of learners' language skills and qualitative data were generated by interviews and classroom observation. The sample comprised of seven grade six and seven (multigrade) classes in seven primary schools (five experimental schools and two comparison schools) in the deep rural area of the Tyumie Valley in the Eastern Cape. Mean score differences between the experimental and comparison groups for the reading, writing, listening and speaking aspects of the literacy test were analysed using Analysis of Co-variance (ANCOVA) techniques. Qualitative data generated were used to gain insights into the statistical findings. The data suggest that the scientific literacy strategy statistically significantly improved the learners' reading skills in English, their listening skills in both English and isiXhosa, and their writing in isiXhosa over the course of one academic year.