Background: The angiographic no-reflow phenomenon after percutaneous coronary intervention (PCI) is associated with a poor clinical prognosis of acute myocardial infarction (AMI). In the present study, we investigated whether chronic antihypertensive treatment according to type of antihypertensive drugs may prevent no-reflow in hypertensive patients who underwent PCI for AMI. Methods: A total of 2260 hypertensive patients (64.9짹12.0 years, male 65.9 %) with AMI (1329 ST segment elevation MI and 920 non-ST segment elevation MI) who were registered in Korea Acute Myocardial Infarction Registry from Nov. 2005 to Dec. 2007. were enrolled. All of the patients underwent PCI. Angiographic no-reflow phenomenon after PCI was defined as Thrombolysis in Myocardial Infarction (TIMI) flow grade <3. Results: No-reflow phenomenon after PCI occurred in 7.5 % of the patients. Patients with no-reflow were older, and had higher Killip class and lower left ventricular ejection fraction (LVEF) and more complex lesions. The level of creatine-kinase MB was significantly higher in patients with no-reflow than those with normal reflow. The 641 patients receiving chronic calcium channel blocker (CCB) treatment before admission had lower incidence of the no-reflow than those without it (5.3% vs. 8.4%, p=0.012). They also showed lower rate of in-hospital death (IHD) (3.6% vs. 6.6%, p=0.005). There was no significant difference in the incidence of the no-reflow between the patients with and without chronic pretreatment of angiotensin II receptor blocker (ARB) or angiotensin converting enzyme (ACE) inhibitor. Multivariable logistic regression analysis revealed CCB pretreatment (OR, 0.61, 95% CI 0.42-0.90, p=0.013) was a significant predictor of the no-reflow phenomenon along with LVEF on admission (OR, 1.87, 95% CI 1.28-2.73) and preprocedural TIMI grade 0/1 flow (OR, 2.85, 95% CI 1.95-4.15, p< 0.001). Conclusion: Chronic pretreatment of CCB is associated with the reduction of the no-reflow phenomenon and in-hospital death in the hypertensive patients with AMI with treated PCI.