The outcome of 14 pregnancies with severe rhesus alloimmunization was analyzed over a period of 16 months. Group A consisted of 7 cases who received ultrasound guided intravascular intrauterine packed red blood cell transfusions via the umbilical vein after determining fetal blood group and hematocrit. The outcome of these cases was compared with another 7 cases (Group B), who did not require intrauterine transfusions. The 7 cases in Group A received a total of 25 intrauterine transfusions between 25 to 33 weeks gestation. Procedure related complications encountered were transient fetal bradycardia on 4 occasions, difficulty in cord cannulation due to fetal movements in 2 cases and transient bleeding at puncture site in 2 cases. These complications were not associated with any maternal or fetal consequences. There was no procedure related mortality. Mean cord hemoglobin in Group A (12.52 g/dl) was significantly higher (p < 0.05) than in Group B (8.5 g/dl), and mean cord indirect serum bilirubin was significantly lower (p < 0.1) in Group A (2.5 mg/dl) than in Group B (5.8 mg/dl). Three neonates in Group A required one exchange transfusion each, as compared to all 7 in Group B who required a total of 12 exchange transfusions. All neonates in Group B survived, whereas 2 expired in Group A, one of severe intravascular coagulopathy and the other due to prematurity and hyaline membrane disease. Percutaneous ultrasound guided umbilical blood transfusions directly into the vascular system appears to be safe in experienced hands and has the potential to improve the prognosis of the severely alloimmunized fetus.