In this paper, a case study is presented based on one school, conducted to examine the factors that influenced the process and quality of implementation of the Tier 1 Program of the Project P.A.T.H.S. Through interviews with the school contact person and focus group interviews with the instructors, an integration of the findings showed that several factors related to the program, people, process, policy, and place (5 “P”s) facilitated the implementation process of the Tier 1 Program in the school. Obstacles and difficulties with reference to the 5 “P”s that affected the quality of implementation were also identified. Overall, the quality of program implementation in the school was good, and the program was well received by the program implementers. Implications of the present findings for future program implementation with reference to school administrative arrangements and implementation issues are discussed.