In the field of education, globally, teachers are recognised as important contributors in shaping learners' interaction in a cooperative learning environment through effective lesson planning. There is a plethora of research conducted internally on lesson planning, as a critical instructional competency for good teaching and as a purposeful activity that precedes the delivery of instruction. This study aimed to explore Life Orientation teachers' lesson planning incorporating a cooperative teaching and learning approach in secondary schools in De Aar, South Africa. The researchers adopted a mixed-methods phenomenological research design. Seven Grade 10 Life Orientation teachers were purposely selected to collect semi-structured interviews data, nonparticipatory observation, and document analysis. Data were analysed using inductive thematic analysis and supported with the literature review and the theory underpinning this study. This paper suggests an enactment between teachers' subject and pedagogical content knowledge and instructional material. Lastly, it is also evident that many teachers lack knowledge, insufficient instructional resources, and an understanding of effective lesson planning to implement a cooperative teaching approach.