This article outlines the impact of an eight-week Precision Teaching (PT) intervention on the sight vocabulary, reading fluency and reading attainment scores of a group of Irish primary school pupils. This study also sought to evaluate the role of PT in facilitating formative assessment of pupils' progress. Employing a mixed-method approach, this study comprised a quasi-experimental design and qualitative interviews involving 40 Irish primary school pupils and seven Learning Support Teachers. Following intervention, a mixed between-within subjects analysis of variance confirmed the differential growth in sight vocabulary scores across the control and intervention groups. Notably, the latter group displayed a greater increase in magnitude in sight vocabulary following intervention, paralleled by statistically significant increases in reading accuracy, fluency and comprehension standard scores and overall reading ability composite scores. Semi-structured interviews highlighted PT as an effective strategy in facilitating formative assessment and a highly motivational tool in education. Results are interpreted in light of relevant literature, with implications for practice and future research discussed.