Since receiving US regulatory approval in 2006 for the treatment of patients with myelodysplastic syndromes, decitabine has also gained marketing approval in several other countries. Rates of complete remission (CR) reported for decitabine range from 9% in the US registration trial to 34% in a study of novel treatment schedules, while reported overall improvement rates range from 30% to 73%. Further studies are needed to determine the relative merits of decitabine compared with azacitidine, the optimal decitabine dose and schedule, how best to proceed following CR, molecular predictors of treatment response, and the possible role of this agent in combination regimens.