The incidence of congenital heart diseases accounts for 8-10 over 1000 liveborn. In Italy about 4000-4500 babies each year are born with congenital heart diseases; 50% of those babies (2000-2200) need cardiac surgery shortly after birth or within the first few months of life. Of the remaining 50%, half undergoes cardiac surgery later on in life and half does not necessitate any surgery; 30% of all cardiac operations consist of palliative procedures and the remaining 70% consist of one-stage corrective procedures. Improvements achieved both in surgical and anesthesiologic techniques, and in cardiopulmonary bypass and myocardial protection, have led to better results in pediatric cardiac surgery, with excellent long term survival rate, even for the more complex variants of congenital heart malformations. Therefore anesthesiologists are now more often required to deal with patients affected by congenital heart defects, for other than cardiac problems. Accurate investigation of patient's clinical history is strongly suggested. Moreover knowledge and familiarity with the modifications of the physiology, occurring in congenital heart disease patients, are mandatory for the choice of the more appropriate anesthesiologic strategy for each patient, in order to optimise the risk-benefits ratio and achieve a less traumatic impact on the cardio-circulatory and respiratory equilibrium. With the aim of achieving better results, interaction between anesthesiologist, cardiologist, pediatrician, surgeon and sometime neonatologist and cardiac surgeon, is strongly recommended in the evaluation of risks, and in decision making of strategies and timing of treatment.