Neuroblastoma is the most frequent extracranial solid tumor of early childhood. Histologically and genetically, neuroblastoma represents a heterogeneous group of tumors with significant differences in clinical behavior. In the past, several different characteristic chromosomal aberrations of neuroblastoma have been described, of which a deletion on chromosome 1p and N-myc amplification have been shown to be of major prognostic significance. However, the role of various other nonrandom DNA imbalances in tumor development and progression needs to be clarified. Taking advantage of the recently established comparative genomic hybridization (CGH), we show that this method is able to accurately detect chromosomal imbalances of known prognostic impact. As CGH gives a comprehensive picture of genetic imbalances in just one experiment, it additionally sheds light on other abnormalities of possible prognostic relevance. We therefore recommend further use of this method not only in the field of research but also for the purpose of genetic routine diagnostics in neuroblastoma.