Two hundred and twenty-six patients were diagnosed with myelodysplastic syndrome (MDS), according to the French-American-British (FAB) criteria, over a 13-year period, and studied retrospectively in a single institution in order to study indicators which were prognostically significant. Analysis of clinical and laboratory data indicated that the FAB classification, the Bournemouth, Dusseldorf, Goasguen, Sanz and FAB Scoring Systems were all good predictors of survival. We found advancing age, haemoglobin (Hb) < or = 9 g/dl, platelet count < or = 50 x 10(9)/l, increased peripheral total white cell count (WCC) and monocytosis, increased bone marrow blasts, dysgranulopoiesis, and bone marrow fibrosis were significant adverse prognostic variables. The commonest complication and cause of death was infection; however, infective episodes were not significantly associated with low neutrophil counts (either < or = 1.5 x 10(9)/l or < or = 0.8 x 10(9)/l) and there was also no significant association between neutropenia and survival. These findings indicate that neutrophil dysfunction plays an important role in the clinical progression of patients with MDS. The effect of new therapeutic modalities, such as the haemopoietic growth factors, on reducing infective episodes may be as significant as their effect on increasing neutrophil counts.