This study presents the results of fine needle aspiration cytology in a series of 26 consecutive children with neuroblastic tumours. The cytological spectrum varied from undifferentiated small tumour cells to mature ganglion cells in a fibrillar background. In 24 children with neuroblastic tumours at onset the cytological diagnosis was correct in 21 cases, whereas two aspirates yielded nondiagnostic necrotic material and a fibrillar material without tumour cells, respectively. One necrotic lymph node aspirate was initially incorrectly diagnosed as lymphoma, but the diagnosis was later revised to neuroblastoma. Suspected signs of disease progression or relapses were confirmed (n = 9) or ruled out (n = 1) using aspiration cytology. The diagnostic accuracy in the complete series was 97% (31/32) in cases with adequate smears. Immunocytochemistry confirmed the cytological diagnosis in 14 of 15 cases and was decisive in one. Elevated catecholamine metabolites in urine was detected in all children with a cytological diagnosis of neuroblastoma. General anaesthesia was only performed when coincidental invasive investigations (n = 13) were to be carried out or if the aspiration was intrathoracic (n = 6). It is concluded that aspiration cytology in conjunction with immunocytochemistry offers a safe, rapid and accurate diagnostic method which may be useful, together with analyses of catecholamine metabolites in urine, in the clinical management of children with neuroblastic tumours.