The concept of imperfect market structures enables learners to develop mathematical and graphing skills that are needed for them to be critical thinkers and to be able to solve problems faced in their daily lives. It also provides opportunities for learners to acquire economic knowledge, which enables them to make informed economic decisions on economic events and issues they will experience as they enter the world of business and work. In spite of the importance of imperfect market structures in cultivating these skills and knowledge, learner academic achievement in economics, particularly where mathematical and graphing skills are concerned, has been regrettably poor in most countries around the globe. Hence, this qualitative study investigated the opportunities to learn mathematical and graphical skills in imperfect market structures in three selected Grade 12 economics classes. The study intended to investigate what it is that teachers do in the name of teaching and learning of mathematical and graphing skills and the reasoning behind their actions. Opportunities to Learn (OTL) is the conceptual framework which was used to determine what teachers do in the classroom that enables learners to make sense of imperfect market structures. Using the case study approach, the study was operationalised by three conveniently selected economics teachers in the Galeshewe township in South Africa. The researcher conducted semi-structured interviews with each of the three teachers before they conducted their classes which the researcher observed. The findings of the researcher show that little or no opportunities to learn are provided in an imperfect market structure class.