ystic kidney diseases are being diagnosed earlier and earlier (1) because of more accessible routine prenatal US and advances in US technology. However, differential diagnosis often remains a challenge because kidney cysts can arise in a large variety of illnesses, imaging patterns evolve over time, and extrarenal features of systemic diseases may not be present at a young age. Thus, imaging findings for a particular disease in newborns may be different from those in adolescents, and predicting prognosis or deciding on optimal follow-up intervals can be challenging. Imaging can contribute not only to accurate diagnosis and prognosis but also to rational management of cystic nephropathies. In adults with autosomal dominant polycystic kidney disease (ADPKD), for example, total kidney volume measured at MRI has emerged as a useful tool with which to identify patients who will benefit from treatment (2); however, transfer and adaptation of these findings to children is still an important research need. The purpose of this consensus statement is to establish uniform standards for choosing the correct imaging modality and diagnostic criteria for the most common cystic kidney diseases in childhood and adolescence and to propose rational approaches to diagnosis and follow-up in important clinical settings. The spectrum of diseases covered here includes simple cysts; multicystic dysplastic kidneys (MCDKs); cystic dysplasia and HNF1B-associated disease; autosomal recessive polycystic kidney disease (ARPKD) and ADPKD; other ciliopathies, such as nephronophthisis and Bardet-Biedl syndrome; acquired cystic kidney disease