This study investigated the predictive value of red blood cell distribution width (RDW) stent length for in-stent restenosis (ISR) drug-eluting stent implantation in patients with acute myocardial infarction. Reliable predictors of restenosis remain limited, highlighting the need for accessible clinical markers. A total of 170 patients who underwent stent implantation were included and classified into restenosis and nonrestenosis groups based on follow-up coronary angiography at 12 months. Clinical characteristics and laboratory parameters were compared between groups. Multivariate logistic regression and receiver operating characteristic analyses were performed to evaluate associations and predictive performance. The results showed that RDW and stent length were significantly higher in patients with restenosis and were independent predictors of restenosis risk. The combined use of these variables demonstrated improved predictive performance compared to using the variables individually. In conclusion, RDW and stent length are significant predictors of ISR and may serve as practical indicators for risk stratification in patients undergoing stent implantation.