Most organizations implement evaluation studies to determine how to improve a program or to decide if a program should be continued. However, evaluation can be used to help organizations make relevant and valid decisions for the cycle of program planning, development, implementation, and operation. This article describes a "comprehensive evaluation model" used at Sacred Heart Child and Family Centre,' Toronto, Ontario, that provides a framework for understanding the importance of evaluation activities within all program phases. Four sequential evaluation stages are presented as the framework for the Sacred Heart model, and it is argued that consideration of these stages is essential to an adequate assessment of a program's efficiency and effectiveness. The use of the comprehensive evaluation model is illustrated through two case studies: the design and implementation of an automated management information system and an evaluation of a primary prevention program.