The educational systems of many countries, including Zanzibar, are moving toward accepting learners with moderate intellectual impairment (LWMII) alongside their peers. This qualitative case study investigated inclusion barriers faced by learners with moderate intellectual impairment LWMII in Zanzibar primary schools. The research focused on three key areas: practical barriers encountered in educational settings, attitudinal barriers hindering inclusion, and existing policy barriers that impact educational access and participation for LWMII in Zanzibar’s primary education system. Data were collected through semi-structured interviews and focus group discussions with 45 participants, including teachers, learners, parents, school administrators, and education officers from two purposefully selected primary schools. Inductive thematic analysis revealed several barriers. Practice barriers included a shortage of skilled teachers, large class sizes, and a lack of in-service training. Teachers’ negative attitude barriers lead to segregation. Policy barriers included the absence of inclusive education frameworks and curriculum guidelines for teaching LWMII. The study suggests that all educators should undergo training to instruct LWMII. Additionally, vocational training centers need to hire a sufficient number of specialists with diverse expertise. Finally, schools throughout Zanzibar must be equipped with adequate resources and facilities that enable them to enroll and teach LWMII.