Cross-case analyses of factors that influence the process and implementation quality of the Tier 1 Program of the Project P.A.T.H.S. based on seven cases were carried out. Systematic and integrative analyses revealed several conclusions. First, several factors related to policy, people, program, process, and place (5 “P”s) were conducive to the successful implementation of the Tier 1 Program in the schools. Second, there were obstacles and difficulties with reference to the 5 “P”s that impeded the quality of implementation. Third, policy support and people (especially commitment and passion of the principals, senior school administrators, and program implementers) are two main groups of factors that influence the quality of program implementation. Fourth, although there were different arrangements for program implementation, incorporation of the Tier 1 Program into the formal curriculum was a sound and viable strategy. Fifth, implementation of the Tier 1 Program in schools that admitted students with high or low academic achievement was viable. Sixth, the program was generally perceived positively by the program participants and implementers. Finally, the program implementers perceived the program to be beneficial to the program participants.