High-intensity statins have been recommended to initiate in patients after acute coronary syndrome (ACS) to reduce the risk of death and recurrent cardiovascular events. There have been few studies comparing the effectiveness of high-intensity statins in Vietnam. Therefore, we conducted a randomized controlled trial to compare the effects of rosuvastatin versus atorvastatin in Vietnamese patients with ACS. A total of 96 ACS patients were randomized into 2 groups at a ratio of 1:1 to receive rosuvastatin 20 mg/day or atorvastatin 40 mg/day in addition to the standard treatment of ACS. LDL-c and hs-CRP levels were measured before and after the intervention for analysis. No significant differences were found between the two groups at baseline. LDL-c levels were significantly reduced from baseline to 4-day in both groups (p<0.001 in both groups), but the difference in LDL-c levels at 4-day between the groups was not statistically significant (p=0.251). hs-CRP did not increase significantly in the rosuvastatin group but significantly in the atorvastatin group (p=0.209 and p<0.001, respectively). hs-CRP at 4-day was not significantly different between the two groups (p=0.250). The proportion of LDL <1.8 mmol/L after 4 days in the rosuvastatin group was significantly higher than that of the atorvastatin group (OR=4.592; 95% CI 1.365-15.449; p=0.014). There was no significant difference in the LDL-c reduction ≥50% and hs-CRP ≤3 mg/L at 4-day between two groups. In conclusion, rosuvastatin is more effective than atorvastatin in achieving LDL-c targets of <1.8 mmol/L after 4 days in Vietnamese patients with ACS.