Objective. To assess the incidence and outcome of heparin-induced thrombocytopenia type II in children after correction of congenital heart defects. Material and methods. A retrospective analysis of the electronic database of patients aged 0—17 years was performed. All patients underwent surgical correction of congenital heart disease for the period from January 1, 2013 to December 31, 2018. Results. Incidence of heparin-induced thrombocytopenia type II in children after correction of congenital heart disease is 0.81%. There were no significant differences of this value between boys and girls. Children with complex, combined, ductus-dependent heart defects have a high risk of heparin-induced thrombocytopenia type II in early postoperative period. Risk factor of heparin-induced thrombocytopenia type II in children with congenital heart disease is early postoperative heart failure. Asymptomatic course of heparin-induced thrombocytopenia type II with favorable outcome was observed in 42.5% of children with congenital heart disease, complicated course with thrombosis and fatal outcomes — in 57.5% of cases. Conclusion. To date, clinicians refer heparin-induced thrombocytopenia type II as «chimera». Physicians continue to prescribe heparin despite high risk of this pathology and laboratory verified diagnosis of heparin-induced thrombocytopenia type II. According to our data, it is necessary to change attitudes towards patients with heparin-induced thrombocytopenia type II.