Small study sizes are a limiting factor in assessing outcome measures in pediatric cardiology. It is even more difficult to assess the outcomes of congenital catheterizations where the sample sizes are even smaller, particularly on a individual institutional level. The creation of multicenter registries is a method by which investigators can pool data to better assess quality and outcome measures of these procedures. No registry is perfect with several being available today, each with its own strengths and weaknesses. In addition, there are a multitude of methods currently used to assess quality and outcomes from the data contained in these registries, each having its own limitations as well. Nonetheless, multicenter registrities remain one of the best available options to improve the quality of care for pediatric interventional cardiac catheterization. Below, we provide an overview of the current state of quality assessment/improvement in pediatric interventional cardiology including a review of the available registrities and the metrics used to measure quality of care and outcomes.