We describe the clinicomorphological features in 33 cases of primary myelodysplastic syndrome classified according to the FAB classification which presented to a single centre over a 12 year period. Presenting features were typically related to pancytopenia although hepatosplenomegaly and granulocytic sarcomas were far more prevalent than in the adult population. Morphological assessment of the peripheral blood and the bone marrow showed seven patients had refractory anaemia (RA), 13 patients had RA with excess of blasts (RAEB), nine patients had RAEB in transformation (RAEB-t) and four patients had chronic myelomonocytic leukaemia (CMML). The overall mean survival was short (9.9 months) in all the subgroups and the leukaemic transformation rate was high. None of the patients scored 0-1 according to the Bournemouth Scoring System; four patients scored 2 whereas 29 patients scored 3 to 4. We conclude that unlike adults, the myelodysplastic syndromes in children run an aggressive clinical course, irrespective of the FAB subtype, and the pathogenesis of these diseases in paediatric practice warrants scientific scrutiny. Intensive chemotherapy such as the one used in de novo-AML lead to complete remission in some children and these early results suggest that this should be the treatment of choice in paediatric MDS.