As clinical judgment has joined forces with evidence-based medicine, nephrologists critically assess the validity of the data available to support therapeutic decisions for children with kidney disease. Unfortunately, a paucity of data often prevents the practice of evidence-based medicine. Three scenarios illustrating the status of evidence and clinical decision making are provided. A review of the pediatric nephrology literature supports a call for general support of ongoing clinical trials and encourages the creation of additional feasible clinical trials to improve the practice of medicine.