Öz:INTRODUCTION: Conventional cytogenetic analysis is very helpful in monitoring both the diagnosis and the course of the disease in children with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Some chromosomal abnormalities can be seen in specific subgroups of leukemia. In addition, some of the structural and numerical chromosomal abnormalities carried by the patients are good prognosis indicators, while others are bad prognosis indicators. In this study, we investigated the correlation between the cytogenetic analysis results and clinical parameters of the 26 pediatric leukemia patients diagnosed with AML and ALL. METHODS: Conventional cytogenetic analyzes of patients were made by examining metaphase chromosomes obtained from non-induced bone marrow samples by Giemsa-trypsin (GTG banding) method. RESULTS: Various structural and numerical anomalies were detected in both AML and ALL patients. These abnormalities were compatible with the literature, and they were also compatible with the types of leukemia of the patients. The complex karyotypes were found more in the AML patients group than in the ALL patients group. In addition, three chromosomal anomalities which are seen very rarely were detected in 1 ALL and 2 AML patients. DISCUSSION and CONCLUSION: Despite the presence of advanced molecular cytogenetic techniques, conventional cytogenetic analysis still has an important value.