Aim To investigate risk factors of intraoperative bradycardia during primary percutaneous coronary intervention (PPCI) in patients with first acute ST-segment-elevation myocardial infarction(STEMI). Methods Totally 448 first acute STEMI patients who had PPCI in Beijing Anzhen Hospital, Capital Medical University were enrolled. All patients were divided into two groups according to intraoperative bradycardia:intraoperative bradycardia group (105 cases, preoperative heart rate was greater than or equal to 60 times/min, intraoperative heart rate was less than 60 times/min persistent or transient) and control group (343 cases). Totally 32 clinical and angiographic items were recorded. Risk factors of intraoperative bradycardia during PPCI for first acute STEMI were analyzed. Results In present study, a frequency of intraoperative bradycardia was 23.43%(105/448). Complete block of culprit vessel, culprit vessel being left anterior descending coronary artery, culprit vessel being right coronary artery, single vessel/multiple vessels lesion, no-reflow, high density lipoprotein cholesterol, creatinine, and hemoglobin had significant differences in the two groups of patients (P＜0.05) among the 32 involved factors. Multivariate logistic stepwise regression showed that no-reflow (odd ratio＝3.3,5% confidence interval:1.479～6.223) and culprit vessel being right coronary artery(odd ratio＝2.2,5% confidence interval:1.602～4.391)were independent risk factors predicting intraoperative bradycardia during PPCI with first acute STEMI. Conclusion No-reflow and culprit vessel being right coronary artery are independent risk factors predicting intraoperative bradycardia during PPCI in patients with first acute STEMI.