The role of the "principal" in encouraging and supporting parent involvement has not received as much research attention as it would seem to merit. While the recent literature on parent involvement is extensive, virtually none are devoted to investigating the impact of school leadership, particularly the function of the principal on parent involvement. The purpose of this study is to examine the role of the principal in improving the level of parental involvement and its relative impact on student achievement. For the purpose of this study, 250 secondary school administrators from Title I schools of the Southern California school districts were sampled through an available sampling technique. The resultant sample for the final analysis was 93 parent involvement designees. A correlation research design was used to examine the relationship among principals' leadership, six types of parent involvement, and student achievement. Specifically, multiple regressions as well as path model analysis were employed as the analytical techniques. The result of the analysis showed that among Joyce Epstein's six types of parent involvement (parenting, communicating, volunteering, learning at home, decision making, and collaborating with the community), communicating, volunteering, decision making and time allocation were the significant predictors of academic performance index (API) scores in schools. However, in the face of the free lunch consideration in an economically challenged environment, such as those investigated in this study, the API of schools are only significantly predicted by two types of parent involvement, communicating and decision making. Recommendations based on the findings to the educational practices and policies were discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]