We report the data of CD34+ cell immunoselection from peripheral blood after G-CSF-alone mobilization (10 micrograms/kg/d s.c.) in nine children with neuroblastoma (median age 4-5 years (2-8), median body weight 16 kg (10-20). Leukaphereses were carried out on a Cobe Spectra separator and two consecutive harvests (4 blood volumes processed) were used for immunoselection on a Ceprate column. The yield of CD34+ cells in the purified fraction was 50% (23-80), with a median number of 2.8 x 10(6) CD34+ cells/kg (1-9.4). All patients were reinfused with selected CD34+ cells after busulfan 600 mg/m2 +melphalan 180 mg/m2 and achieved successful haemopoietic recovery.