The study sought to investigate the role of Heads of Departments (HoDs) in the teaching of mathematics in primary schools of the Eastern Cape Province in the OR Tambo Inland District using a qualitative approach and a case study design in particular. Data was collected using both semi-structured and focus group interviews with eight purposively selected heads of departments in the district in six schools. Data was analysed using Colaizzi’s method of data analysis from which three themes emerged. The first one was that the current performance management system interfered with the roles and responsibilities of the HoDs in schools in their daily activities and in the organisation of their work. Second, the barriers in achieving learners’ good performance in mathematics interfered with the HoDs’ responsibilities to achieve good learner performance in the subject. Third, a weak support system and inadequate resources interfered with the learners’ performance in the subject. The results here indicate that HoDs for mathematics experience various obstacles, which affect subject teachers’ implementation to yield positive results, ultimately leading to poor teaching and learning of the subject. These include the admission of learners without the necessary foundations in mathematics which was viewed as an obstacle to learner performance. The study further suggested that the HoDs of mathematics should be capacitated on use of teaching aids, management and administration to improve learner performance in the subject. / Educational Management and Leadership / M. Ed. (Education Management)