Abstract: AIM:To examine whether plasma smooth muscle myosin heavy chain (smMHC) can be used to predict restenosis after intracoronary stenting. METHODS: Eighty patients undergoing successful intracoronary stenting were followed by coronary angiography for 6 months after intracoronary stenting. In the restenosis group there were 12 patients and in the control group were 68 patients who had no restenosis after intracoronary stenting. smMHC levels were measured (ELISA) using smMHC-specific monoclonal antibodies by enzyme-linked immunosorbent assay before surgery and after stenting. RESULTS: Plasma smMHC levels between groups before surgery were not statistically significant, but after stenting, plasma smMHC levels were significantly higher than the preoperative smMHC levels (P<0.05). Plasma smMHC levels in restenosis group were significantly higher than those in the control group (P<0.05). CONCLUSION: Plasma smMHC levels after stenting are significantly increased, which are associated with in-stent restenosis. Plasma smMHC levels can be used as a biochemical marker for the prediction of in-stent restenosis.