Due to improvements in the intensive care and surgical management of children with heart disease over the last three decades, early operative mortality for paediatric cardiac surgery is now very low: the raw 30-day mortality rate from Registry data is 2–4%. As operative survival has increased, the current expectation is that most children with heart disease will survive admission to an intensive care unit and grow into adulthood. There are an increasing number of survivors with congenital heart disease (CHD) of greater complexity as well as children with associated comorbidities and those who require serial interventions. More complex patients spend longer periods in the hospital and are exposed to a greater risk of complications, which may include renal and liver injury, myocardial injury and long-term myocardial failure, brain hypo-perfusion, stroke and other thromboembolic complications, seizures and neurodevelopmental (ND) delays. Any or all of these complications impact long-term patient quality of life. It has been argued that intense scrutiny and reflection on outcomes leads to healthcare improvements, which are clearly of great importance for the overall well-being of patients and their families. Local, national and international efforts have explored new ways to evaluate outcomes, analyse the data and share results with stakeholders.