OBJECTIVES: To describe outcomes and economic impact of hypomethylating therapy (Decitabine / Azacitidine) compared to transfusion therapy in adult patients with Myelodysplastic syndrome (MDS) non-candidates to transplant. METHODS: Was building a Markov Model simulating the disease with 6 stages; Myelodysplastic syndrome in treatment, Complete + Partial + Hematologic Response (C+P+HR), transfusion independent, transfusion dependent, Myeloid Leukemia and Death. Every medication was compared with each control group in two different simulations because the characteristics of every control group were different. We were interested in finding the incremental values in outcomes and costs of each treatment. Our case base was an adult patient with MDS non-candidate to transplant. The Temporal Horizon was 1 year, perspective of insurer and mortality avoided progression free disease (PFD) and survival as outcomes. The statistics inputs of the model for the transitions were the Kapplan-Meier curves of Kantarjian H and Fenaux P papers. Were used direct costs from a private hospital in Bogota, Colombia and government prices according regulation laws. RESULTS: The simulation project incremental effectiveness for both hypometilants compared with transfusion therapy. In terms of C+P+HR was 40% for Decitabine and 28% for Azacitidine, in PFD was 73% for Decitabine and 76% for Azacitidine and survival was 50% for Decitabine and 37% for Azacitidine. Compared with transfusion therapy Decitabine was a cost-saving alternative (better results with lower costs)   vs. cost-effectiveness for Azacitidine (better results with higher costs). CONCLUSIONS: In Colombia the hypomethylant therapy with Decitabine is a cost-saving alternative compared with transfusion therapy.