An embryonal rhabdomyosarcoma was analyzed cytogenetically after short-term culturing. The tumor was located in the scrotum of an 18-year-old man who, at the age of 4, had been treated for a rhabdomyosarcoma in the orbita. The chromosome number was 100. No structural aberrations were present. There were 2-7 copies of each chromosome type with particular excess of chromosomes 8, 12, and 22, and a relative deficit of chromosome 15.