Eisenmenger's syndrome is characterized by a right-to-left or bidirectional shunt in congenital heart diseases. Hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome, commonly occurring during pregnancy, includes hemolysis, elevated liver enzymes and low platelet counts. HELLP syndrome and pregnancy are extremely rare in patients with Eisenmenger's syndrome. The authors report 4 cases of pregnancy complicated by the HELLP and Eisenmenger's syndrome and describe their initial intervention and the in-hospital outcomes of these cases. Special emphasis is given to elaborate about the hemodynamic monitoring, magnesium sulphate for convulsions, corticosteroid treatment, anticoagulation therapy, management of pulmonary hypertension, the timing of delivery, and blood product transfusion.