The purpose of this article is to investigate the challenges encountered by school principals and teachers in South African schools in ensuring that instructional time is optimally used during contact time. Challenges that impede the optimal use of instruction time are extensively investigated as they are encountered daily by school principals and teachers. This article therefore sought to understand the impact of these challenges on the smoothing flowing and delivery knowledge during teaching and learning activities. In this article, data was collected through semi-structured interviews and document analysis. School principals and post level 1 teachers were individually interviewed with the intension to investigate and understand what challenges do they encounter during contact time in regard to the optimal use of instruction time. All interviews were then transcribed, coded and themes developed. School principals and teachers from township schools encounter similar challenges with their counterparts in former Model C schools. However, if all school principals work hand in gloves with teachers and other stakeholders, then a number of challenges encountered they encounter will be minimised resulting in improved learners’ academic performance. Some participating teachers could have some reservations to speak openly particularly if the challenges were as a result of some weaknesses pertaining to how their school principals manage instruction time. As subordinates, teachers could try to protect their school principals in fear of being victimised regardless of being assured of their names’ anonymity and confidentiality of the information shared. This article’s finding and recommendations thereof may be used by the school principals, teachers and the Department of Basic Education as source of information in identifying the timewasters that impedes the optimal use of instruction time and the strategies that can be employed in order to minimise or eradicate them. Based on this study, school principals and teachers can revisit the way they deal with such challenges with the aim to improve the effective use of instructional time. This article provides both theoretical and empirical contribution to the existing literature on the challenges encountered by school principals and teachers pertaining the optimal utilisation of instruction time. In addition, it also highlights some recommendations that give advice to school principals and teachers on how they can minimise or eradicate these challenges for the betterment of learners’ academic performance.