This study was conducted in order to assess the effectiveness of practitioner training in underprivileged early childhood settings. The quantitative study set out to test a target group of 800 Grade R children, ranging in age from five to six and a half years, in order to determine the impact that practitioner training on early intervention has on young children. A pre-test evaluated the initial level of each child‟s abilities, including physical-motor, language and speech, cognitive, play and social and emotional development. Children were placed into control and experimental groups through random selection of practitioners. The experimental group's teachers (practitioners) underwent an eight-month part-time intervention programme which focused on the importance of early intervention, the domains of development, planning, preparation and assessment as well as encouraging community awareness. The control and experimental groups continued with their normal school programmes, but the practitioners in the experimental group were developing a deeper understanding of early childhood development and activities which enhance development in children. The results indicate that the impact of effective practitioner training and enhancing a deep understanding of stimulation in young children can have positive, long-term results in children's cognitive ability, laying foundational concepts and scope for development. Vast differences were noted in the ability level of children which were stimulated, as compared with those children who were not as stimulated. / Psychology of Education / D. Ed. (Psychology of Education)