Social skills and social emotional learning (SEL) are fundamental to children's mental health, academic learning and motivation to cooperate and achieve. Social skills and SEL are also significant predictors of school achievement, problem behaviours and school attendance. In line curriculum, personal and social capability is now an integral component of the new Australian Curriculum. This paper outlines preliminary information on the comprehensive and longitudinal (4 year) implementation of a proactive SEL intervention by classroom teachers with all students in Preparatory to Year 3 in a low socio-economic status (SES) school setting in Australia. The social skills improvement system (SSiS) [1] has recently been applied in Australian schools [2]. This paper provides insights into the applicability of the SSiS in this challenging setting. The SSiS has been recognised as a most comprehensive system of assessing, targeting and then developing specific social skills to individual students and to whole classrooms [3]. This paper also outlines the use of the SSiS Screening tool for all students and the use of a Rating Scale for students with low Prosocial behaviours, so as to identify social skills for targeting, for the subsequent delivery of social skill training to the whole class, rather than intervention to individuals. The paper also raises the importance of training teachers as social skills classroom interventionists, particularly in early year classrooms. Preliminary data on student social skill development in the first year of the research program, along with teachers reflections provide evidence of the efficacy of the SSiS as a classroom intervention program in this setting. This intervention model of training classroom teachers to assess and then deliver social skills to their students with support from school psychologists is reviewed as a potential strategy to meet the expectations of the personal and social capability domain of the Australian Curriculum.