Many of the recurring chromosome abnormalities reported in leukemia and lymphoma cells are believed to be an integral part of the malignant transformation. They are useful adjunct to other laboratory and clinical tests to help to detect malignant neoplasms, to classify malignant disorders, to characterize the degree of malign progression, to test for remission and to establish when relapse occurs. Although analysis of bone marrow chromosomes is becoming such an essential component in the investigation of hematological diseases, it is frequently hampered by the poor quantity and quality of chromosomes obtained. In the study 6 cases with malignant hematologic disorder were tested for non-random chromosome abnormalities by bone marrow and peripheral blood cultures and the technical problems were discussed.