Amniocentesis is an invaluable diagnostic tool. In the hands of the experienced, the complication rate is small but not unimportant. The possibility of puncturing the fetus at any point, injecting dye into the fetus, introducing infection, precipitating fetomaternal hemorrhage, or traumatizing the placenta must always be kept in mind. Fetal position must be known prior to the amniocentesis to minimize the possible trauma which the fetus may receive during this procedure. Those responsible for the perinatal care of mother and baby must be alert for the complications of this procedure.