Eisenmenger syndrome is a dramatic complication of certain heart diseases. It is an absolute contra-indication to pregnancy because it holds a high risk of maternal-fetal mortality. Nowadays, we don´t see much of this condition, because congenital heart defects are diagnosed during childhood, infancy, or prenatally; and even if a pregnancy occurs, it is usually terminated as soon as it is diagnosed. Nevertheless, some women are willing to carry the risks that come with their condition. We report the case of a 26-year-old woman with an undiagnosed interventricular septal wall defect that evolved into Eisenmenger syndrome during her pregnancy. A successful elective C-section was done under epidural anesthesia and close monitoring. When facing this challenging situation, there are no clear guidelines, however, premature and elective delivery is paramount.