Current therapy for children with cancer includes a variety of invasive procedures many of which require repeated venous access over a considerable period of time. Such procedures are poorly tolerated by children and by their veins. Recently it has become possible to undertake the majority of such procedures by means of permanent indwelling silastic catheters improving the quality of life of the children and their parents and increasing the scope of therapeutic intervention. In the period July '83 - August '84 we have used 46 of these catheters in 45 children with malignant disease, 12 with acute myeloid leukaemia, 12 with neuroblastoma, 7 with B cell leukaemia-lymphoma, 6 with rhabdomyosarcomas, 2 with Ewing's Sarcoma, 2 with Wilms' tumor and 1 case each of Hodgkin's disease, teratocarcinoma, osteosarcoma and juvenile chronic myeloid leukaemia. The children's ages ranged from 2 months to 14 years; 22 were male and 23 female. The catheters were inserted under general anaesthesia (duration 20-40 minutes) usually without difficulty, except for a single patient in whom no suitable vein could be found. No complications connected with the placement of the catheter were observed. Subsequent management of the catheter was initially complicated and time-consuming, but was subsequently simplified so that acceptance by parents, children and nursing staff was eventually excellent. The duration of use of 46 catheters ranges from 7 to 350+ days; 24 catheters are presently in use at 30-350+ days from insertion. Eight children died as a result of disease progression and two of sepsis with the catheter in place.(ABSTRACT TRUNCATED AT 250 WORDS)