This paper reports on the challenges facing the South African PIRLS with regard to the implementation of the international project within a multilingual and multicultural context. Several additional elements have been included in the South African project to cope with this environment. One of these is the translation of the assessment into all 11 official languages which has uncovered the language and cultural complexities of translation. A number of modifications had to be made that illuminate the importance of diverse contexts and cultures in cross national studies. These represent challenges of cross-national validity in terms of the instruments. Although the international study focuses on Grade 4, the rationale being that by this age, experts have found that reading has normally been established, this is the age in South Africa where the majority of learners make the transition of learning in an additional language. Pupils in South African begin their schooling through the medium of their mother tongue (one of the official 11 languages) and the medium only changes to either English or Afrikaans at the beginning of grade 4, this introduces another complexity in the South African study and is one of the original reasons for testing in all 11 official languages. The transition in the language of learning is seen as the root cause for many learners struggling to access information within the classroom. For the majority of learners (more than 70%), this additional language (usually English) is experienced as a foreign language as they seldom speak or hear the language outside the classrooms. This is especially true in rural areas. Therefore the South African study also includes Grade 5 pupils in addition to the international requirement of grade 4 pupils. Given this transition phase and the expected difficulties of South African Grade 4 learners, the inclusion of Grade 5 learners as an additional sample (and national option) is expected to reveal the rate of progress in adopting the new language of learning over the two years period of transition and to provide a reliable measure of literacy. Furthermore, the background questionnaires will allow one to assess what the differences in reading levels between locations in South Africa and in particular the difference in instructional practices across South African schools and identify good practice. A key component of this study is to identify what is needed to improve the reading literacy of young children in South Africa in terms of teacher development and to further ascertain to what extent do teacher education levels have an impact on reading literacy in schools? Finally, this paper will elaborate upon the national options introduced by the South African team in an effort to enhance the current international design of PIRLS and to increase its relevance within a developing context.