The purpose of the study was to evaluate the prognostic value of the detection of tumor cells in the bone marrow (BM) in children with neuroblastoma (NB) by flow cytometry. The detection of tumor cells was performed in BM of 51 patients with NB (24 boys and 27 girls) aged from 6 days to 15 years (median--1 year 3 months). Flow cytometry allowed determining NB cells in BM in a much larger number of cases than cytomorphology (49.0% and 29.4% of patients, respectively). Patients, in whom NB cells were not detected in BM by flow cytometry, had significantly better event-free and overall survival rates as well as progression free survival (83.5%, 87.7% and 86,8%, respectively) compared with those in whom immunophenotyping revealed the tumor cells (28.0%, 35.87% and 34,3%, respectively). The prognostic value of the detection of BM lesion by flow cytometry was also confirmed in selected groups of patients with other criteria of stratification. Therefore the detection of tumor cells in BM by flow cytometry could potentially be considered in conjunction with other factors in choosing treatment strategy in patients with NB.