We analyzed the use of non-tunneled (polyurethane, double lumen) central venous catheters (CVCs) for the collection, conditioning, transplantation and immediate post-transplantation periods in 56 children with various malignant diseases. A total of 71 leukaphereses were performed, with a mean of 1.2 apheresis per patient, following administration of granulocyte colony-stimulating factor (G-CSF) using a continuous flow blood cell separator (Cobe Spectra). The mean TBV (total blood volume) processed was 4.5 +/- 1.2 s.d. (range 2.4-7). The mean flow rate was 30.6 ml/min and the duration of a single apheresis was 327 +/- 84 s.d. (range 175-511 min). The mean purities and efficacies of collections were 77.38 +/- s.d. (range 42-100) and 42.78 +/- s.d. (range 24-80), respectively. The mean numbers of mononuclear cells (MNC) and CD34+ cells collected were 9.3 +/- 6.9 s.d. x 10(8)/kg (range 2-49) and 6.2 +/- 7.2 s.d. x 10(6)/kg (range 1-42), respectively. We observed the following complications during catheter insertion for collection: pneumothorax (1.7%), mechanical dysfunction (3.5%) that resolved with thrombolytic therapy. Complications during conditioning, transplantation and immediate post-transplantation periods were entry site infection in five patients (8.92%), catheter-related infection in two (3.57%) and catheter-related sepsis in three (5.35%). Our results indicate that the collection of PBSC with non-tunneled catheters is safe, effective and dis associated with a low incidence of complications.