While much progress has been made in relation to including students in mainstream education in Ireland, significant challenges remain. Despite positive attitudes, the implementation of effective inclusive practice at school level persists as one of the most pervasive challenges. This study investigated how six Irish schools, three primary and three post-primary, grappled with the challenge of implementing good inclusive practice for three different groups of students: students with special educational needs, students at risk of educational disadvantage and students from minority ethnic groups for whom English was not their first language. Using a multiple case study design, involving students, teachers, parents and a range of auxiliary school staff, a data-set was generated consisting of 312 completed questionnaires, transcripts from 72 interviews, 10 student day-long observations, documents and student drawings. Analysis of the data revealed challenges and barriers to inclusion at three levels: that of the school, the teacher and the child/family/community. Practical examples of how the six schools addressed these challenges are offered at the level of the school, where there was a focus on strong leadership; of the teacher, which centred around meeting individual students' needs; and of the child/family/community, where collaboration as well as social and affective issues, were addressed. The examples of how the schools addressed these challenges have relevance beyond Ireland. They are not dependent on extra financial resources or large-scale interventions. Instead, the evidence of good practice described in this article offers practical advice and credible illustrations, which schools may find helpful in their attempts to move beyond positive attitudes to including the full diversity of students in mainstream schools.