There is widespread recognition that surgical outcomes differ by surgeon and institution; however, the definition and measurement of quality in pediatric cardiac surgery is in its infancy. This article discusses the definition of quality, what has been done to define and measure quality of pediatric cardiac surgery, and how to proceed. Descriptions of assessment of quality by evaluating structure, process, and outcome measures; efforts to establish a global congenital heart surgery database; and a comparison of risk-adjusted mortality rates using the Risk Adjustment for Congenital Heart Surgery method are included.