Background: The Platelet Inhibition and Patient Outcomes (PLATO) study found that ticagrelor plus aspirin (TA) was more effective than clopidogrel plus aspirin (CA), without an increase in the risk of massive bleeding in patients undergoing percutaneous coronary intervention (PCI). Data from other studies indicate that the conclusion is controversial with the results obtained by PLATO. Aim: To investigate the efficacy and safety of TA, compared with CA, in patients with acute coronary syndrome (ACS) after PCI. Methods: A systematic literature search was performed in the MEDLINE, EMBASE, and Cochrane databases to compare the efficacy and safety of CA and TA treatment in patients with ACS after PCI. The endpoints were major adverse cardiac events (MACEs), death, stroke, myocardial infarction (MI), stent thrombosis, and bleeding events. The data analysis was performed using RevMan 5.3 software, and the odds ratios (ORs) and their 95% confidence intervals (CI) were calculated. The standards of reporting were in accordance with the PRISMA guidelines. Results: 13 studies with a total of 58,062 patients were included in this study with a subgroup analysis of the European/American and Asian populations. In terms of effectiveness for MACEs, the European, American and Asian populations benefitted more from the TA treatment than the CA treatment (European and American populations, OR = 0.82, P = 0.0002; Asian, OR = 0.66, P < 0.0001; total, OR = 0.78, P < 0.0001). In terms of specific effectiveness indicators, such as stroke, MI, and stent thrombosis, the results of TA and CA groups in the European, American, and Asian populations were not consistent. In terms of safety, there was no statistical difference in total bleeding events between TA and CA treatments (OR = 1.19, P = 0.21). However, in the Asian population, the incidence of total bleeding events (OR= 1.52, P = 0.0004) in the TA group was higher than that in the CA group. Conclusion: The TA treatment in the European and American populations is more beneficial and safer than CA treatment. However, although the Asian population has this benefit, the risk of bleeding is significantly increased as well, and antiplatelet drugs should be chosen carefully.