Critical pathway methodology has been demonstrated to provide producible reduction in average length of stay (ALOS) in adults in certain diagnostic-related groups and operations such as coronary artery bypass grafting. The efficacy of this approach in congenital heart surgery was explored. Two hundred eighty-six consecutive patients from a health maintenance organization treated by a single surgeon since the institution of diagnostic-related group coding at that health maintenance organization constituted the study group. One hundred fourteen patients were treated at a university hospital without critical pathway methodology (group 1) and 172, subsequently at the health maintenance organization institution using the methodology (group 2). Operation/lesion, age, and diagnostic-related group matching was possible in 61 pairs. Examination of the ALOS Hospital (operative and postoperative days) for the entire cohort revealed a 43.8% reduction in ALOS Hospital (p < 0.0001) and a 39.0% reduction in ALOS Intensive Care Unit (p < 0.0001). There was also significant reduction in ALOS Hospital and ALOS Intensive Care Unit in the operation/lesion-matched subsets. Outcome measures including operative and late mortality, readmission, unscheduled emergency room and clinic visits, and health maintenance organization family assessment survey demonstrated no improvement in outcome with increased hospital stay. Thus, critical pathway methodology when used in patients undergoing a congenital heart operation produces a significant reduction in hospital stay and intensive care unit stay as well as quality patient care with uniformity of outcome.