Over the past years significant progress has been made in the treatment of childhood cancers due to newer and more intensive chemotherapeutic regimes. However, with the increased intensity of chemotherapy, more treatment related complications are seen, requiring also more aggressive supportive care. The major complications of the cytotoxic treatment are bone marrow aplasia, immunosuppression, vomiting, anorexia and weight loss and supportive measures as adequate blood component supply, prophylaxis, recognition and effective treatment of infections as well as parenteral hyperalimentation are corner stones of modern cancer therapy. Blood sampling, application of blood products or intravenous drugs and continuous parenteral nutrition is easily performed using a central venous line. Our experience with the continuous venous access of central lines in patients receiving aggressive cytotoxic treatment did not show a higher incidence of infectious complications but had significant advantages in the supportive care.