The results of a direct cytogenetic tumor analysis in a 2 1/2-year-old girl with metastatic neuroblastoma are presented in this paper. Investigations established a modal karyotype of 46 chromosomes with several marker chromosomes. Besides del(1)(p31), hsr, and dmin chromosomes in all the cells analyzed, terminal deletion of the long arm of chromosome 14 was also identified. Malignant cells were thus monosomic for segment 14q24----qter.