Objective: To assess the safety and effects of 40 mg atorvastatin on serum lipids, inflammatory markers and clinical events in ACS patients post PCI., Methods: A total of 92 patients with ACS post successful PCI were randomly divided into atorvastatin 10 mg/d (group A) and atorvastatin 40 mg/d (group B) on top of the standard medical therapy. Blood were taken at baseline, 4, 12 and 24 weeks for serum alanine aminotransferase (ALT), lipids, high-sensitive C-reactive protein (hs-CRP) and matrix metalloprotease-9 (MMP-9) measurements. The major adverse cardiac events (MACE) were also observed., Results: There was no significant difference in medication withdrawn (2 vs. 3 cases) due to increased ALT (3 times higher than normal) and incidence of MACE (5 vs. 7 cases) between the groups. TC and LDL were significantly reduced in both groups 4 weeks and thereafter post medication compared to pre-treatment (P < 0.05) and the reduction was more significant in group B than that in group A at 24 weeks post medication (P < 0.05) while TG and HDL remained unchanged. hs-CRP was significantly reduced at 12 and 24 weeks in both groups compared to baseline and the reduction was more significant in group B than that in group A at 24 weeks. MMP-9 was significantly reduced in both groups 4 weeks and thereafter post medication compared to pre-treatment (P < 0.05) and the reduction was more significant in group B than that in group A at 12 weeks post medication (P < 0.05)., Conclusion: Both atorvastatin doses significantly reduced TC, LDL, hs-CRP and MMP-9 in ACS patients post PCI and the reduction was more significant in high dose atorvastatin group at 24 weeks while the MACE and drug withdraw rates were similar between the groups.