There is a significant gap in the academic achievement of children living in poverty and their peers. The research, Improving Literacy Achievement in a High-Poverty School: Empowering Classroom Teachers Through Professional Development, aimed to reduce the gap in children's educational attainment by targeting pupils in high-poverty schools, since a substantial proportion of these pupils they fell short of their capabilities. Literacy, which can be considered as the ability to read and write, can be one of the factors contributing to children's poor performance. Several methods have been initiated with the aim of reducing this barrier. Although this goal has not been achieved, some schools have managed to improve children's literacy levels. Evidence from numerous large-scale studies has shown that teachers need to be equipped with specific skills to effectively teach literacy. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an Original Essay This study was completed through an in-depth analysis of the literacy skills of four first-grade classes from a high-poverty school, who were ultimately promoted to second grade during the study. Participants in this study included fifty-six students, twenty-five boys and thirty-one girls, the parents of these children, classroom teachers, and four special education teachers at the school. With the aim of collecting data effectively, a multilevel triangulation research design was used, which is a mixed methods approach. Both quantitative and qualitative data contributed significantly to the results. Quantitative data were collected through the implementation of questionnaires, assessments of writing samples, and MANOVA and posthoc tests. Qualitative data was collected through conducting interviews, digital recordings of professional development sessions, and observations of literacy lessons in each classroom throughout the study. The data were analyzed using the constant comparative method, which facilitated multiple comparisons between the qualitative and quantitative data. The use of codes was also implied, using an inductive approach until connections were observed, leading to combining information into themes. The analysis procedure can be considered recurrent, since continuous experimentation between qualitative and quantitative data has been approved. Regardless of limitations such as insufficient time for literacy instruction, a limited amount of time for additional planning (away from professional development sessions), methods of improving school attendance, and methods of enhancing parental involvement, the Initial results established a significant increase in the academic achievement or literacy skills (reading, writing and spelling) of participating pupils. According to Eithne Kennedy, an increase of more than half in deviation was reflected on the Drumcondra sentence reading test, between January of first grade and June of second grade. The number of pupils performing below the tenth percentile was dramatically reduced by three quarters and twenty per cent of pupils managed to achieve above the eightieth percentile, a result which had not been achieved at the start of the programme. Furthermore, pupils' overall quality, expression and spelling also revealed notable improvements,..