This study explicated the theory underpinning the Human Ecology Practicum Program offered in the Department of Human Ecology at the University of Alberta. The program has operated for 40 years but never been formally evaluated. Using a document analysis, focus group and individual interviews, and a stakeholder working group, we explored stakeholder perspectives on the purpose, design, and logic of the program. Findings indicated a common understanding among stakeholders about the fundamental purpose and design of the program, and about the mechanisms by which design features lead to program goals. Findings were used to develop the theory of the Human Ecology Practicum Program. In addition to providing a case example of practicum program theory development, our study demonstrates the value of involving stakeholders in theory development and supports the articulation of program theory as part of course planning and evaluation within postsecondary education programs.