This study aims to identify the importance of parental involvement in student academic achievement in Tamil School through school, family and community partnership. This study focuses on the involvement of parents on six main aspects of Epstein's theory: parenting, communication, home-based learning, decision-making, community collaboration and volunteerism. These aspects enable parents' involvement and collaboration with schools and outside communities in order to improve students' academic achievement. Questionnaire and respondent interview were used as research instrument. The study involved naturalistic investigation utilizing semi-structured interviews on four primary school headmasters from high and low achievement schools as study sample. Meanwhile 285 teachers with more than 15 years of teaching experience were used to collect quantitative data via a questionnaire. The data was processed using SPSS program to obtain frequency, percentage, mean score, Pearson correlation and canonical correlation. While thematic analysis was used to report the interview findings. The findings showed that there was a significant positive relationship between parents involvement and in the improvement of academic achievement of the students, namely in the aspects of home teaching, parenting, decision-making and volunteerism aspects. As a conclusion, some new suggestions were made to enhance the involvement of parents in the academic achievement of the Tamil school students.