Congenital heart disease (CHD) is the commonest birth defect, and children may present at all ages with variably corrected lesions for both elective and emergency surgery. No single anaesthetic approach can be recommended in this heterogeneous group of children, so a general strategy is presented based on applied physiology and the available evidence. Pathophysiological patterns are presented along with the common physiological consequences of cardiac disease in children: cardiac failure, cyanosis, pulmonary hypertension and arrhythmias. Children with congenital heart disease presenting for non-cardiac surgery are at increased perioperative risk compared to their unaffected peers. Risk factors are identified, and a scoring system to predict in-hospital mortality is presented. Preoperative assessment encompasses consideration of the optimal location for surgery as well as specific considerations, including echocardiography, infectious endocarditis prophylaxis and pacemaker/ defibrillators. In general, a balanced anaesthetic technique including controlled ventilation and opioids to reduce volatile exposure is preferred. However, with appropriate understanding of the underlying physiology, most anaesthetic techniques can be used safely and successfully in children with CHD.