A number of prognostic scoring systems for patients with myelodysplastic syndromes (MDS) have been introduced in the past. In the present study, survival and AML evolution were analyzed retrospectively in a total of 180 patients with de novo MDS (observation period: 1989-1999; median age: 71; range 27-93; f/m ratio: 1/1.2). Diagnoses were established according to FAB criteria (RARS, n=37; RA, n=53; RAEB, n=50; RAEB-t, n=19; CMML, n=21). Six different multiparameter scoring systems (the Mufti, Aul, Sanz, Morel, and Toyama scores, and the international prognostic scoring system [IPSS]) were applied. The Aul, Sanz, and Mufti scores were applied to all 180 patients, Morel and Toyama scores to 109 patients, and the IPSS to 102. As assessed by multivariate analysis, the percentage of bm-blasts, hemoglobin, platelet count, neutrophil count, LDH, and karyotype were found to be independent single variables for survival, and bm-blasts, neutrophil count, platelet count, and karyotype for AML evolution. All prognostic scoring systems applied appeared to be highly predictive for survival and AML development (P<0.001). The highest predictive values were found for the Aul, Sanz, and Toyama scores for overall survival, and the IPSS, Toyama, and Morel scores for AML-free survival. In summary, our data show that scoring systems are useful for predicting overall and AML-free survival in patients with MDS. Karyotype-based multiparameter systems appear to be particularly effective in defining MDS patients who are at high risk of transforming to leukemia.