Cytogenetics investigations, mostly from peripheral blood, were carried out in 30 children with CML. Amongst a sample of 30 patients, 18 had chronic myeloid leukemia of adult variety (ACML), while the remaining 12 children had the juvenile type of chronic myeloid leukemia (JCML). Sixteen (88.9%) out of the 18 patients suffering from ACML tested positive for the classical Philadelphia chromosome translocation t(9; 22). Of the remaining two ACML patients, one tested positive for t(9; 13; 22) while no visible chromosomal changes were observed in the other patient. The activity of Nucleolar Organizer Region (NOR) was significantly reduced in 11 (61.1%) of the 18 patients suffering from ACML, when compared to that of 21 normal healthy controls. Ten out of the 12 patients suffering from JCML had normal karyotypes, while monosomy 8 and 21 q deletion were seen in the remaining two patients respectively. Amongst the 30 CML patients, chromosomal abnormalities were observed in 19 patients. Variant Philadelphia chromosome translocation (9; 13; 22) and monosomy B were observed in ACML and JCML, respectively. In two ACML patients, cytogenetic studies were helpful in diagnosis of the disease.