The findings of the Progress in International Reading Literacy Study (PIRLS) 2006 highlighted concerns about support for and the quality of reading literacy teaching in South African primary schools. In South Africa there is a paucity of research outlining schooling conditions and teachers’ reading literacy teaching practices especially in the Intermediate Phase. The aim of this mixed methods study was to explore schooling conditions and teaching practices for the implementation of the curriculum for Grade 4 learners’ reading literacy development across a range of education contexts. Two research sub-questions explored in two research phases were used to investigate the overall question which was: What influence do schooling conditions and teaching practices have on curriculum implementation for Grade 4 reading literacy? In phase one, PIRLS 2006 principal and teacher questionnaire data were re-classified for secondary analysis according to language of instruction (English First Language or English Additional Language) and the mean performance of each participating class of learners on the PIRLS 2006 international benchmarks and further benchmarks established to reflect the performance of the majority of South African learners. Response distributions on selected classroom level variables detailing teacher characteristics and reading literacy teaching practices as well as selected school level variables describing teaching conditions impacting the teaching of reading literacy were compared across each reclassified benchmark sub-sample. In phase two, six school and teacher case studies were purposively selected from each of the sub-samples to complement and extend the findings from the analysis of the survey data using multiple qualitative data sources. The findings revealed that differences in schooling conditions and teaching practices across the PIRLS achievement spectrum were generally aligned to differences between advantaged, high achieving schools and disadvantaged low-achieving schools. Thus, the study provides insights into the high levels of between-school inequalities for the development of Grade 4 reading literacy and school and classroom level reasons for such inequalities. On the basis of the findings, recommendations for policy, teacher practice and teacher education, and further research are provided.