The last decade has seen an increased focus through policy and research for schools to move towards an evidence-informed practice. Although some practitioners now access the external research evidence when deciding which interventions to adopt in their school, research suggests many still do not. Instead, approaches to teaching and learning are often informed by trends and the opinions and experiences of practitioners. Little is known about what intervention programmes/approaches are used in schools and whether they are evidence-based. We conducted this study to assess the range and evidence of interventions used in a school cluster in Wales, which comprised two secondary schools, seven primary schools and one special school. Using questionnaires, we evidenced 242 interventions. Following screening, we included 138 of these in the analysis and categorised them according to the ‘SEN Areas of Need’. We then conducted a rapid systematic review of the literature for these interventions and found that 30% had some evidence of positive impact on pupil outcomes, 67% had no published evidence, and 3% had causal evidence to suggest they were ineffective. One year later, we conducted a follow-up study to assess if schools’ knowledge of the evidence for the interventions, presented through a summary report, had an impact on their provision. Our data suggest that the reports had very little impact on existing provision, and some schools continued to use the same interventions. The limitations of this study and directions for the cluster, policy and research are discussed.