Aim To investigate the predictive value of mean platelet volume/lymphocyte ratio (MPVLR) in patients with acute ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (pPCI). Methods From January 2015 to December 2017, a total of 304 patients who underwent pPCI, admitted within 12 hours from symptom onset, were enrolled and divided into two groups based on no-reflow. The platelet/lymphocyte ratio (PLR) and the MPVLR were calculated by collecting baseline data of patients enrolled and preoperative blood parameters. Logistic regression was used to analyze the risk factors. Results In univariate analysis, the lymphocyte count in the no-reflow group was significantly lower than that in the normal-reflow group (P＜0.05); Mean platelet volume, PLR, MPVLR, high-sensitive C-reactive protein(hs-CRP), tirofiban in operation, pain-to-balloon time, and average stent length in the no-reflow group were significantly higher than those in the normal-reflow group (P＜0.05). In multivariate analysis, PLR, MPVLR, and pain-to-balloon time were independent predictors of no-reflow after pPCI in patients with acute STEMI. The area under the ROC curves for PLR and MPVLR were 0.766 and 0.795, respectively. The sensitivity was 73.8% and 88.7%, and the specificity was 69.1% and 64.1%, respectively. Conclusions MPVLR can effectively predict the occurrence of no-reflow after pPCI in patients with acute STEMI. As a calculated value of common indicators from blood routine examination, MPVLR is easy to get and deserved to be generalized.