This research study intended to establish the factors affecting the teaching of children with mental retardation in inclusive setting in Green Hills Academy Primary School in Gasabo District in Kigali city of Rwanda. It was to investigate and identify the possible barriers that affect the teaching of children with mental retardation in inclusive setting and to determine various strategies that could be used to overcome the factors hindering the teaching of children with mental retardation. Structured interview schedules were used to collect the data. It was collected from three categories of subjects, headteacher, teachers and parents. The respondents were chosen to represent the big population of teachers and parents who could not be used by the researcher to give the information.