We report a case of pregnancy in a 34-year-old woman with uncorrected tetralogy of Fallot (TOF). There are more risks in patients without surgical correction. In our case, haemoglobin and haematocrit were higher, oxygen saturation was lower, and right ventricular enlargement was observed. Pregnancy was resolved successfully by caesarean section. Improvement of fetomaternal outcome may be related to corrective procedures before conception to achieve better functional heart capacity. Delicate multidisciplinary medical management is essential for these limited cases to achieve optimal prognosis.