Learners' mathematics performance globally and locally has been a major concern. Learners are generally not performing well in mathematics. This is also true of learners in Kwagga West Circuit, Nkangala district in Mpumalanga province of South Africa. Performing badly in the subject negatively affects them, preventing them from progressing to the next grades. This research employed a qualitative case study design with observation and semi-structured interviews with a sample of three school management team (SMT) members, six teachers, nine learners, and three parent component members of the school governing body (SGB) to determine factors affecting learner performance in mathematics in the senior phase. The results showed that numerous factors influenced learners' confidence and performance. The factors found to have an impact on mathematics performance were learner related, such as ill-discipline, language barriers and learner attitudes. Teachers' factors included lack of pedagogical content knowledge and skill, and lack of appropriate professional training. Finally, the study offers suggestions for further research and recommendations regarding learners, teachers, schools, school management teams, the parents, as well as for the national education ministry.