Korean middle school students have shown outstanding performance in various international assessments since a decade ago. The current study focused on parental variables and their relations to their children's achievement. In this study, the researcher sought to explore how parental variables such as parental involvement, attributions, education, and income influence performance of Korean youths. Completed questionnaires from 138 Korean parents whose children are middle school students were analyzed to answer the research questions. The analyses of data in this study confirmed that parents' educational level, private tutoring expenditure, satisfaction with private tutoring, parents' home and school based involvement, parents' perception of their children's GPA, parents' attribution of luck, effort, and strategy to their children's academic success were associated with children's achievement in Korean families. The results of this study indicated that not only parental involvement in home based and school based activities, but also private tutoring based activities, were positively associated with Korean middle school students' achievement. In particular, parents' involvement in private tutoring based activities was a strong factor to enhance children's achievement in core academic subjects (math, Korean, English). The findings of this study suggested that Korean parents' involvement includes the private tutoring system as well as home and school involvement, and this unique aspect of parental involvement is used as an important strategy to promote children's academic achievement by current Korean parents.