Objective To explore the impact of controlling nutritional status and prognostic nutritional index on the prognosis of patients with myelodysplastic syndrome. Methods The clinical data of 119 patients with myelodysplastic syndrome treated in the department of Hematology of our hospital from March 2010 to December 2020 were retrospectively analyzed. The optimal cut-off point of observation index was calculated according to the receiver operating characteristic curve （ROC）. CONUT score and PNI were grouped based on the cut-off points of 4 and 36.75, respectively, and the differences between age, gender, blood cell count and IPSS scores were analyzed. The prognostic factors were analyzed via univariate and Cox multivariate regression analyses. Results The univariate analysis revealed that age, platelet count, bone marrow blast cell count, IPSS scores and CONUT were risk factors for the prognosis of patients with MDS. The multivariate analysis revealed that bone marrow blast cell count （HR = 1.06, 95%CI:1.01 ~ 1.12, P = 0.028） and CONUT （HR = 0.606, 95%CI:0.39 ~ 0.95, P = 0.028） were independent prognosis risk factors of patients with MDS. Conclusions High CONUT score in newly diagnosed MDS patients indicates poor prognosis and is an independent risk factor for MDS prognosis, while PNI is not an independent risk factor for MDS prognosis. [ABSTRACT FROM AUTHOR]