Information and communication, technology (ICT) has become a necessary tool in education post-COVID-19 pandemic. However, integrating ICT into teaching and learning has been a daunting challenge in many developing countries, such as Uganda. This qualitative case study investigated the challenges that primary school teachers face in implementing ICT in teaching science, technology, engineering, and mathematics (STEM) subjects in Uganda. The study found various challenges divided into three categories: infrastructure and internet connectivity; individual factors and administrative support; and curriculum and learner support materials. A significant obstacle was the lack of computer access, internet connectivity, and ICT textbooks. Additionally, teachers lacked the ICT skills necessary to integrate technology into their teaching methods, and administrative support was insufficient. The identified challenges in this study will require a multi-pronged approach that includes increasing investment in infrastructure, providing training and support to teachers, and developing relevant and appropriate ICT curriculum materials. In conclusion, this study highlights the challenges that primary school teachers face in implementing ICT in teaching STEM subjects in Uganda. By addressing the identified challenges, policymakers and stakeholders can take steps towards improving ICT integration in primary school education and bridging the digital divide in developing countries.