The extreme variability in prognosis among patients with myelodysplastic syndromes (MDS) complicates decision-making regarding their therapy. Several studies carried out in recent years have recognized the prognostic value of some clinical and biological characteristics. The percentage of blast cells in bone marrow, cytopenias, age and chromosome abnormalities are the most relevant factors affecting outcome. More importantly, some of these studies have resulted in the development of prognostic regression formulas and scoring systems for accurately estimating the individual prognosis of patients. The major aim of this review is to offer the clinician useful tools for treating MDS patients on a risk-fitted strategy.