Objective To investigate the relationship between platelet/hemoglobin ratio(PHR)and the severity of diabetic foot ulcer(DFU)and its predictive value for DFU progression.Methods A retrospective study was performed in 345 DFU patients treated in Department of Endocrinology,the First Affiliated Hospital of Army Medical University from March 2018 to March 2023.Their general demographic information was obtained,and the results of laboratory tests,including hemoglobin Alc(HbA1c),fasting plasma glucose(FPG),biochemical and related blood routine indicators were collected.According to Wanger grading,the patients were assigned into mild(n=145)and severe ulcer groups(n=200).The demographic data and clinical parameters were compared between the 2 groups.Multivariate logistic regression model was applied to identify the independent predictors for severe ulcer in DFU,and receiver operating characteristic(ROC)curve was plotted to evaluate the predictive performance of PHR for DFU progression.Results The severe ulcer group presented remarkable increases in male proportion,HbA1c and FPG levels,platelet(PLT)count and PHR when compared with the mild ulcer group(P＜0.05).Multivariate logistic regression analysis revealed that PHR and male were independent risk factors,while,HDL-C was a protective factor for progression to severe ulcer in DFU patients(P＜0.05).ROC curve analysis showed that the area under the curve of PHR for predicting severe ulcer was 0.701(95％CI:0.646～0.756).Conclusion PHR is strongly associated with the severity of DFU,and shows certain predictive value for the progression to severe ulcer in DFU patients.