The field of children's interstitial lung disease (chILD) has been confusing for clinicians and families. It is fraught with imperfect pediatric definitions and classification systems, limited understanding of underlying molecular mechanisms, pathophysiology and natural history, and inadequate clinical networks to improve care. To address these issues two large efforts have focused on chILD: a European Respiratory Society (ERS) Task Force on chronic interstitial lung disease in children and the National Institute of Health (NIH)-sponsored Rare Lung Disease Consortium (RLDC). Collaborative efforts in chILD research have retrospectively studied large numbers of children with ILD using different strategies. Both efforts have yielded new concepts and approaches to the evaluation of pediatric patients with ILD. Diagnostic techniques have also evolved to provide more advanced testing in children. This article reviews the current evaluation for children with ILD and highlights areas of controversy.