This study investigated the theory-practice gaps in implementing constructivist instruction at the University of Gondar, focusing on the Colleges of Education and Social Sciences. Using a qualitative research approach, specifically a single case embedded unit design, the study involved fourteen participants purposefully selected, including instructors, department heads, and college deans. Data were collected through interviews, classroom observations and course plan reviews. To triangulate the data, eight classrooms were observed and four course plans were reviewed. The findings reveal that instructors possess sufficient theoretical understanding of constructivism, which they conceptualize as both a process of student knowledge construction and a student-centered pedagogical approach. However, this understanding is often undermined by their instructional practices, which remain predominantly teacher-centered, reliant on traditional lecture methods and behaviorist-oriented assessments. The study identified major challenges to implementation, including inadequate student prior knowledge, lack of instructor commitment, and insufficient materials aligned with constructivist principles. However, the study also noted opportunities for improvement, such as access to digital technology. The study concludes that this disconnect is not rooted in a lack of knowledge, but in systemic and contextual barriers that prevent the effective application of constructivist principles The study suggests universities revise programs and offer professional development for educators. College deans and head of departments should support instructors better by creating space for practicing constructivist principles, and instructors should adjust their lessons in line with constructivist ideals.