Inclusive education (IE) was introduced in 2001 in South African schools. Still, its implementation in mainstream classrooms has not attained optimum potential. To highlight the shortcomings, this study explores factors preventing teachers from effectively implementing IE in a combined school. Qualitative data were collected through interviews, questionnaires, and document analysis. Thematic analysis results revealed teacher preparedness, among other factors, is impeding the effective implementation of IE in schools. Bronfenbrenner's theory emphasised the need for collaboration to achieve systemic goals. The study recommends education authorities consider the shortcomings to strengthen teacher efficacy and student support, including endorsing school infrastructure IE compliant.