In women with a significative mitral stenosis that become pregnant, medical treatment has limitations and surgical treatment is associated with maternal and fetal mortality. We report two pregnant women in whom a mitral valvuloplasty was performed in weeks 30 and 32 of pregnancy, using the single balloon Inoue technique. The indication for the procedure was the persistence of functional capacity IV heart failure in spite of hospital bed rest and the use of diuretics and beta-blockers. Basal mitral valvular area was 0.6 and 0.9 cm2 and improved to 1.7 and 1.8 cm2 after the procedure; six months later, the areas were 1. 5 and 1. 7 respectively. The procedure was well tolerated and was performed with abdominal and pelvic shielding. No complications occurred, which a#owed hospital discharge in functional capacity I; they were readmitted for delivery, giving birth to two healthy girls. It is concluded that mitral valvuloplasty in safe and effective in pregnant women with mitral stenosis refractory to usual medical treatment.