Analysis of the chromosomes of a cloned human hepato-blastoma cell line, HUH-6-clone 5 by Q-, G- and C-banding revealed numerical and structural chromosome aberrations. The modal number of chromosomes was 49. Trisomies #12 and 20 were present in most of the cells, and 8q isochromosome was detected in all of the cells analyzed. High levels of alpha-fetoprotein production by this cell strain were also demonstrated.