Congenital heart defects are the most common cause of death in infants and young children in the developed world. As the mortality in this population has declined to less than 5%, more attention is being focused now on reducing post-procedural morbidities that may seriously impact the patient and their families. Because of multiple reasons, paediatric cardiac surgery and anaesthesia is a perfect model for studying human errors and their impact on patient safety. Congenital cardiac disease is a common lesion causing much morbidity, pain, and loss of life. Over 44,000 surgical procedures are performed yearly to repair congenital cardiac problems in the United States alone. The reduction or elimination of iatrogenic adverse outcomes, given the current mortality rates of 4.2%-4.5%, might lead to as many as 500 children achieving better outcomes or shorter hospitalizations.Efforts to quantify the frequency of complications related to anaesthesia in patients undergoing congenital cardiac surgery have been difficult to date because of the low occurrence of this surgery compared to other surgeries on children and the relatively rare incidence of complications related to anaesthesia in this population. Anaesthesiologists play a crucial role in the reduction, recognition, and timely treatment of medical errors that impact this morbidity. Paediatric cardiac surgery encompasses many complex procedures that are highly dependent upon a sophisticated organizational structure, effective communication, coordinated efforts of multiple individuals working as a team, and high levels of cognitive and technical performance. Human factor error analysis in this patient population has shown how frequently both minor and major errors occur. The goal of this paper is to outline the frequency and sources of these errors and to suggest treatment strategies which may minimize their occurrence.