Objective To investigate the effects and mechanisms of rosiglitazone on the expressions of nuclear factor-κB and matrix metalloprotease (MMP-9) in peripheral blood monocyte-derived macrophages (MDMs) in patients with coronary heart disease. Method This was a clinical case-control study. Forty-eight actue coronary symdrome (ACS) patients (ACS group), and 20 patients with stable angina (SA) (control group) were collected. They were performed coronary arteriography in the Department of Cardiology of the Second Xiangya Hospital from March to April in 2007. Exclusion criteria included acute infection, trauma or surgery patients within four weeks, cerebral vascular accident, liver and kidney dysfunction, cancer, and so on. The peripheral blood mononuclear cells were isolated and transformed into MDMs with macrophage colony-stimulating factor treatment. The transformed MDMs were randomly assigned into subgrougs and incubated with 0 /μmol/L, 1 μmol/L, 10 μmol/L, 20 μmol/L of rosiglitazone respectively. The expressions of PPAR-γ mRNA, MMP-9 mRNA were determined by RT-PCR and nuclear factor-κB P65 (NF-KB P65) expression by immunohistochemistry. Multiple comparisons were examined for significant differences using analysis of variance (ANOVA). Results The basal expression of PPAR-y mRNA was lower, in contrast, the levels of NF-KB P65 and MMP-9 mRNA were higher in ACS group than control group. PPAR-γ mRNA expression were significantly upregulated in both ACS and control groups with rosiglitazone treatment. PPAR-γ mRNA expression was positive correlation, while the expressions of MMP-9 mRNA were negative correlation with the rosiglitazone concentration in the ACS group. Rosiglitazone inhibited the expression of NF-KB in a concentration-independent manner in ACS and control groups. Conclusions The expression of PPAR-y mRNA is inhibited, while the activity of NF-KB and expression of MMP-9 mRNA are enhanced in MDMs of ACS cases. Rosiglitazone intervention may inhibit NF-KB activity and MMP-9 expression by upregulation of PPAR-y expression in MDMS of patiens with ACS.