Among 171 women who had undergone mitral valvulotomy at childbearing age, 47 had a total of 62 postoperative pregnancies. The cardiological findings before and after valvulotomy show the patients with pregnancy to be a positive selection of all patients who had mitral valvulotomy in Zurich. 10% of the pregnancies were complicated by atrial fibrillation or heart failure. Three deaths related to pregnancy and birth were registered. The NYHA functional classes III and IV are considered to be contraindications for postoperative pregnancy. Other risk factors are discussed. Based on physical examination, electrocardiography, chest x-ray, ergometry and echocardiography, a woman wishing to have a child after mitral valvulotomy should be advised of the cardiological risk. During pregnancy, regular follow-up by both obstetrician and cardiologist must be expressly required.