Abstract: This article reports results of a phase 2 exploratory trial of a vocabulary program delivered in elementary schools to improve student’s reading ability, including their comprehension. The intervention was tested as a targeted intervention in classrooms with children aged 7–10 across 20 weeks during one school year, with eligible students learning in small groups of four. Teachers and support staff received training in this cooperative learning approach to develop children’s vocabulary with particular focus on Tier‐2 words. School staff received additional support and resources to equip them to develop and implement the vocabulary instruction sessions to targeted students. The trial was undertaken with a sample of 101 students in seven schools from three English district areas with high levels of socio‐economic disadvantage. A standardized reading test was used to measure reading outcomes, with significant gains found in student’s overall reading ability, including comprehension. Owing to the positive results found in this trial, including positive feedback about implementation of the technique, next steps should be a larger trial with 48 schools to avoid the risk of sampling error due to limited number of schools.