To determine the diagnostic characteristics, blast crisis status, appropriate treatment, overall patient survival, and prognostic factors pertaining to chronic myeloid leukemia (CML) for children, the authors reviewed 47 children under 18 years of age with CML who were admitted to the National Taiwan University Hospital in the period between 1976 and 2001 inclusively. Between 1976 and 1985, ten patients were diagnosed by clinical manifestation without the application of any cytogenetic study, while from 1986 to 2001, 37 patients were diagnosed as evidenced by the presence of a positive Philadelphia chromosome upon cytogenetic examination. The male-to-female ratio was 0.7 (14 boys/20 girls) for patients under 15 years of age. Abdominal fullness or pain appeared to be the most common presenting symptom, followed by body weight decline and bleeding. Marked leukocytosis, anemia, and thrombocytosis were common laboratory findings in these patients. The incidence of only lymphoid blast crisis was 38%, which appears to be the highest incidence when compared to the corresponding value as reported in other studies. Of 25 children treated with conventional chemotherapy including busulfan and hydroxyurea, the median survival period from diagnosis was 44 and 42 months, respectively. Between January 1984 and December 2001, 22 affected children underwent allogeneic stem-cell transplantation (SCT). The 5-year survival probability following hematopoietic SCT from matched sibling donors is 65%, and 22% following SCT from matched unrelated donors. This difference is statistically significant (p =.01).