Objective To investigate the association between nutritional status and serum hepcidin and pentraxin 3 （PTX3） levels in patients undergoing maintenance hemodialysis （MHD）. Methods A total of 76 patients with MHD who met the inclusion criteria were recruited from the hemodialysis center at the Affiliated Hospital of Chengde Medical University. Nutritional status was assessed using the Subjective Global Assessment （SGA）， which categorizes patients into three grades： SGA?A， SGA?B， and SGA?C. Serum levels of PTX3 and hepcidin were measured by enzyme?linked immunosorbent assay （ELISA）. Statistical analyses were conducted using SPSS software. One?way analysis of variance （ANOVA） was applied to compare differences across the three SGA groups. Logistic regression analysis was performed to identify influencing factors， and receiver operating characteristic （ROC） curve analysis was used to evaluate diagnostic value. Among the participants， 45 patients were classified as malnourished based on SGA?B and SGA?C scores， while those with SGA?A constituted the well?nourished control group. Results Among the 76 MHD patients， 59.2% were malnourished. We then compared clinical characteristics across the three groups. The results showed that the malnourished group was older and exhibited significantly higher levels of hs?CRP， PTX3， and hepcidin （P < 0.05）， while serum albumin， creatinine， and phosphorus levels were significantly lower （P < 0.05）. Pearson correlation analysis revealed positive correlations between SGA grades and hs?CRP， PTX3， and hepcidin levels （all P < 0.05）. Logistic regression analysis with “malnutrition” as the dependent variable indicated that elevated hs?CRP， PTX3， and hepcidin levels， along with age and male gender， were associated with increased risk of malnutrition in MHD patients， whereas higher serum phosphorus and creatinine levels were protective factors. Further multivariate logistic regression analysis demonstrated that serum PTX3 level was an independent risk factor for malnutrition （P = 0.032）， while higher creatinine level was an independent protective factor （P = 0.047）. ROC curve analysis showed that the combination of serum PTX3 and creatinine levels had a high diagnostic value for identifying malnutrition in MHD patients， yielding an AUC of 0.789 （P < 0.001）， a Youden index of 0.448， sensitivity of 77.8%， and specificity of 71.0%. Conclusions Elevated levels of PTX3 and hepcidin， along with reduced serum creatinine levels， are associated with an increased risk of malnutrition in patients undergoing MHD. Notably， elevated serum PTX3 and decreased serum creatinine independently predict malnutrition in this population and demonstrate high predictive value.