No-reflow phenomenon is a serious complication of percutaneous coronary intervention (PCI) which is closely related to the incidence of major adverse cardiovascular events. It has been demonstrated that Postconditioning (PostC) during primary PCI confers protection against ischemia-reperfusion injury and thus might reduce infarct size. However, whether PostC may exert its beneficial effects on acute myocardial infarction (AMI) patients by reducing no-reflow phenomenon is still unknown. Sixty two patients diagnosed with ST-elevation AMI were randomly assigned to study group (n = 32) or control group (n = 30). Blood samples were obtained and assayed for creatine kinase MB (CK-MB) and high-sensitive C-reactive protein (hs-CRP). Determinants of reflow, including final thrombolysis in myocardial infarction (TIMI) grade-3 flow, ST-segment resolution (STR), myocardial blush grades-3 (MBG-3) and corrected thrombolysis in myocardial infarction frame count (cTFC), were comparative between the two groups. Compared with control group, more patients in study group were identified as the final TIMI grade-3 flow (81.3 vs. 56.7%, P = 0.036), MBG-3 (23 vs. 14%, P = 0.043) and STR ≥50% (93.8 vs. 73.3%, P = 0.029), while patients in study group had less cTFC (28.5 ± 9.1 vs. 37.4 ± 12.4, P = 0.002) After PCI, study group was associated with lower levels of CK-MB (2,397.6 ± 470.2 vs. 2,159.9 ± 485.5, P = 0.028), Troponin-I (197.5 ± 32.5 vs. 154 ± 43.1, P = 0.041) and hs-CRP (5.5 ± 4.5 vs. 9.5 ± 5.2 mg/L, P = 0.019) in comparison with control group. Left ventricle ejection fraction was better in the study group than in the control group (55.1 ± 9.8 vs. 42.9 ± 10.7, P = 0.042). PostC could improve myocardial reperfusion in patients with ST-elevation AMI undergoing PCI by reducing no-reflow. However, due to the limited sample size, the results of our study should not be considered conclusive.