In House M.D., what medical department does Dr. House lead?

Dr. House leads the Department of Diagnostic Medicine in House M.D. at the fictional Princeton-Plainsboro Teaching Hospital.

The department specializes in difficult cases that have resisted ordinary diagnosis. House assembles a team of doctors from different specialties, reviews symptoms and test results, and proposes competing explanations before ordering further tests. The department's work provides the show's central engine: each episode turns an unexplained illness into a structured diagnostic investigation.

Diagnostic medicine is not presented as a standard hospital department in exactly the same way in every real-world institution. In the series, it functions as a narrative home for House's unusual expertise and his team-based approach. Viewers may answer “internal medicine” because House is trained in that field, but the department he heads at Princeton-Plainsboro is explicitly Diagnostic Medicine.