Twelve children with a severe form of haemophilia A received a totally implantable venous access system (Port-A-Cath) to facilitate regular prophylactic treatment with factor VIII. The indication for implantation was difficulty in obtaining regular access to a peripheral vein. Postoperative bleeding around the portal site occurred in two of 12 cases. After a median duration of follow-up of 26 months (range 5-79 months), none of the systems had needed replacement due to bleeding, septicaemia or thrombosis. One child, with an inhibitor against factor VIII, had an infection at the portal site and this system was removed. None of the other children had any serious side effects. Nine of the 12 children's parents learned how to use the Port-A-Cath system, thus enabling optimal prophylactic home treatment with factor VIII to be begun early in life.