Presently described is successful cesarean delivery in a pregnancy superimposed on long-term bosentan treatment in an Eisenmenger syndrome patient with cor triatriatum sinistrum, double-orifice mitral valve, and large ventricular septal defect resulting in single functioning ventricle with double outlets. Cesarean delivery was performed at 27th week of gestation without maternal or fetal morbidity. The infant had no congenital cardiovascular abnormality or any probable teratogenic effect of bosentan treatment during pregnancy.