The aim of this study was to explore the teaching of senior phase of Natural Sciences with a focus on the Planet Earth and beyond knowledge strand. A qualitative case study design was used. Semi-structured interviews and observations were employed to collect data from two purposefully chosen teachers. The results of the study showed that some Natural Sciences teachers might lack the appropriate subject matter knowledge for the planet Earth and beyond knowledge strand for meaningful teaching. Moreover, teachers indicated poor knowledge of the context in specific aims and assessment strategies and chose poor and irrelevant instructional strategies. Furthermore, the teachers saw themselves as the authority figure in class and hence applied a dominantly teacher-centered approach. Therefore, it is recommended that there is a need to refocus on the in-service teacher training to improve teachers? subject matter knowledge as well as pedagogic content knowledge. The authors also recommend a large-scale study on the same strand.