We investigated parental origin of rearranged chromosomes 9 and 22 (9q + and 22q -) in five patients with Ph-positive chronic myeloid leukemia (CML) using the C-banding and silver-staining methods of nucleolus organizer regions, respectively; of rearranged chromosome 21 (21q +) in seven patients with t(8;21)-positive acute myeloid leukemia (AML); and of rearranged chromosome 15 (15q +) in six patients with t(15;17)-positive AML. It was found that these rearranged chromosomes can be of either paternal or maternal origin. Although the number of patients examined was small, these results indicate that the genes rearranged as a result of these chromosome translocations (ABL, BCR, AML-1 and PML) are not genomically imprinted.