MDM2/p53 pathway plays an important role in the control of apoptotic and proliferation mechanisms, and alterations in this pathway have been described in myelodysplastic syndromes (MDS). We investigated the frequency of MDM2 SNP309, TP53 Arg72Pro polymorphisms in de novo MDS and the association of these polymorphisms with clinical characteristics. Our results showed that the frequencies of genotypes for MDM2 SNP309 and TP53 Arg72Pro did not differ between MDS and healthy controls and that these polymorphisms were not associated with clinical and laboratory parameters, disease progression and overall survival, suggesting that MDM2 and TP53 polymorphisms are not involved in risk for MDS, or in the clinical and laboratory characteristics of the disease.