Since chromosomal changes are used both as independent prognostic factors and for therapy design in hematological disorders, it is necessary to elucidate chromosomal changes as accurately as possible. We used spectral karyotyping (SKY) and fluorescence in situ hybridization (FISH) to further characterize chromosomal abnormalities in 35 patients with hematological disorders. SKY confirmed 149 aberrations, refined 117, and detected 11 hidden changes. Eighteen abnormalities were detected only by G-banding. Ten monosomies and two deletions described by G-banding were shown to be involved in translocations or ring chromosomes. These results demonstrate that SKY increases the accuracy of karyotype interpretation, which is important for proper diagnosis and management of hematological malignancies.