An interim evaluation was conducted to understand the implementation quality of the Tier 1 Program (Secondary 2 Curriculum) of the Project P.A.T.H.S. (Positive Adolescent Training through Holistic Social Programs) in the Experimental Implementation Phase. Twenty-five schools were randomly selected to participate in personal and/or telephone interviews to provide information on the implementation details of the program and perceived attributes of the worker-support scheme ("Co-Walker Scheme"). Results showed that a majority of the workers perceived that the students had positive responses to the program and the program was helpful to the students. They also identified several good aspects in the program and the Co-Walker Scheme, albeit expressing some negative comments on the program design and difficulties in the implementation process. In conjunction with other findings reported previously, the present findings suggest that the Tier 1 Program is well received by different stakeholders and it promotes the positive development of secondary school students in Hong Kong.