A 28-year-old woman with severe mitral stenosis underwent percutaneous mitral valvuloplasty at 26 weeks' gestation. Balloon dilation using a double 18-18 mm balloon resulted in improvement in mean mitral pressure gradient (32 to 8 mmHg) and in calculated mitral valve area (0.9 to 2.4 cm2) without complications and any evidence of fetal distress during procedures with an estimated radiation exposure to the fetus of 0.13 rem. This procedure resulted in the disappearance of symptoms of congestive heart failure and allowed for normal full term spontaneous delivery of a 3.51 Kg boy without any complication.