Background: Coronary no-reflow (NR) is a dreadful complication of primary percutaneous coronary intervention (pPCI) that is seen in nearly 50% of cases. A great effort is being done to discover simple tools that could predict such a complication. We aimed primarily to study the predictive power of R-wave peak time (RWPT) on NR. Methods: From October 2017 to March 2018, we enrolled 123 patients with STEMI treated with pPCI at Benha University Hospital and National Heart Institute. We measured RWPT from infarct-related artery (IRA) leads and assessed the development of NR in all finally included 100 patients (after exclusions). Results: Based on occurrence of NR, patients were divided into 2 groups; Group I (n = 39) with NR and group II (n = 61) without NR. Smoking, DM, HTN, longer reperfusion times and higher thrombus burden were significantly associated with NR. Both pre- and postprocedural RWPT were significantly higher in group I than Group II. Preprocedural RWPT > 46 ms predicted NR with a sensitivity and specificity of 79.5% and 86.9% respectively (AUC 0.891, 95% CI 0.82–0.962, P < 0.001). In adjusted multivariate analysis, preprocedural RWPT was found to be among independent predictors for NR (OR: 26.2, 95% CI: 6.5–105.1, P < 0.001). The predictive power of preprocedural RWPT was statistically non-inferior to ST-resolution (STR)% (difference between area under curves = 0.029, P = 0.595). Conclusion: RWPT is strongly associated with and significantly predicts the development of NR. This association was statistically non-inferior to the well-known association between STR% and NR.