Hidden behind subtle symptoms and unspecific signs, heart failure in children can pose a significant challenge regarding diagnostic approach as well as treatment strategy. A case report is presented for an 11-month-year-old girl with recurrent airway infections and signs of cardiac failure as a consequence of ventricular non-compaction. This disease is morphologically distinct; most likely a developmental defect of the ventricular myocardium. It is characterized by heterogeneity regarding both heredity, age of presentation, symptoms, hemodynamic disturbances, prognosis and therapeutic approach. In general, a symptomatic child with non-compaction has a poor prognosis with a prospect of severe cardiac failure and death. The article summarises how to approach a child presenting with cardiac failure; i.e. initial evaluation, diagnostic and initial stabilizing procedures and alternative treatment strategies. We also discuss specific treatment of ventricular non-compaction and briefly report on children with non-compaction at the largest pediatric cardiology centre in Norway.