Sixteen children with myelodysplastic syndrome as defined by the French-American-British co-operative group are presented. The mean age was 10.5 (2.5 to 16) years, with a male predominance. All patients belonged to the more aggressive subtypes of myelodysplastic syndromes. Seven patients presented with refractory anaemia with excess blasts, six had refractory anemia with excess blasts in transformation, and three had chronic myelomonocytic leukemia. Cytogenetic analysis done in 7 of the 16 patients, revealed karyotype abnormalities involving chromosomes 7, 8 and 17. One patient with Down's syndrome had karyotype of 47, XY, +21 (major clone) and 46, XY (minor clone). Five of these patients evolved to acute leukemia. The mean duration of survival was 5.5 months. Aggressive chemotherapy as a primary line of treatment induced remission in five out of six patients. Predominance of aggressive types of myelodysplastic syndromes in children and their good but short-lived response to aggressive chemotherapy suggests the need for early bone marrow transplantation following chemotherapy.