Objective To investigate the impact of smoking on the antiplatelet effect of clopidogrel by observing the rate of platelet inhibition between the smoking and non-smoking patients after the administration. Methods A total of 151 patients undergoing percutaneous coronary intervention (PCI) followed by monitoring of thrombelastography (TEG) in the General Hospital of PLA Rockets Force were enrolled in this study. They were divided into smoking group (n=72) and non-smoking group (n=79).The incidences of bleeding and major adverse cardiovascular events (MACE) were recorded in hospital stay and in 6 months after operation, and compared between the 2 groups. Results TEG demonstrated that the platelet inhibition rate (adinosine diphosphate pathway) was significantly higher in smoking group than in non-smoking group in 3 day and 1 month after PCI (80.94±22.57 vs 66.65±26.25,1.64±20.37 vs 69.15±22.89; P<0.05). In 6 months after operation, MACE was reported in 7 cases and minor bleeding in 3 cases in smoking group; MACE was reported in 9 cases and minor bleeding in 4 cases in non-smoking group; no severe bleeding was reported in either group; There were no obvious differences in the incidences of MACE and bleeding between the 2 groups (P>0.05). Conclusion Exposure to smoking may enhance the antiplatelet effect of clopidogrel.