Objective To explore the efficacy of platelet parameters and coagulation markers in the prediction of thrombosis / bleeding events in patients with myelodysplastic syndrome (MDS). Methods Retrospective analysis of 124 MDS patients admitted from July 2022 to August 2024 were studied, grouped according to thrombosis/bleeding, and platelet parameters [platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW)] and coagulation indices [prothrombin time (PT), prothrombin time (TT), fibrinogen (Fib)] differences, and the predictive efficacy of biochemical indices for thrombotic/bleeding events was analysed using subject work characteristics (ROC) curves. Results The number of patients who developed thrombus was 45.97% (57/124), and those who developed haemorrhage was 20.16% (25/124); MDS patients were divided into thrombus group (n=57) and non-thrombus group (n=67), and haemorrhage group (n=25) and non-haemorrhage group (n=99), and the PLT, MPV, and PDW of thrombus group were higher than those of the non-thrombus group (P<0.05), and the patients in haemorrhage group had higher PLT , MPV were higher than those in the non-bleeding group (P<0.05), and the difference in PDW between the bleeding and non-bleeding groups was not statistically significant (P>0.05).PT was lower in the thrombus group than in the non-thrombus group (P<0.05), TT and Fib were higher in the thrombus group than in the non-thrombus group (P<0.05), PT and TT were higher in the haemorrhage group than in the non-haemorrhage group (P<0.05), and Fib was lower in the haemorrhage group than in the non-haemorrhage group (P<0.05). The ROC curves showed that the AUC for the combination of platelet parameters and coagulation indices to predict the development of thrombosis in patients was 0.941 with a sensitivity of 84.22% and a specificity of 94.03%, and the AUC for the combination of platelet parameters and coagulation indices to predict the development of bleeding in patients was 0.984 with a sensitivity of 96.00% and a specificity of 90.91%. Conclusion Multiple indicators, PLT, MPV, PDW, PT, TT and Fib, have high diagnostic efficacy for predicting thrombosis / bleeding events, which provides a new diagnostic scheme for the poor prognosis of MDS patients.