The use of statins in patients undergoing primary percutaneous coronary intervention (PCI) is associated with improved outcomes, but the optimal statin type and loading dose remain unclear. This randomized controlled trial aimed to compare the effects of a loading dose of rosuvastatin versus atorvastatin on immediate post-PCI Thrombolysis In Myocardial Infarction (TIMI) flow and left ventricular ejection fraction (LVEF) at hospital discharge in patients with ST-elevation myocardial infarction (STEMI). 300 patients were enrolled at Mayo Hospital, Lahore, from June 2022 to December 2022. Patients were randomized to receive either a loading dose of rosuvastatin (40 mg) or atorvastatin (80 mg) before primary PCI. There was no significant difference in the proportion of patients achieving TIMI flow grade 3 immediately after PCI between the rosuvastatin and atorvastatin groups (74% vs. 72%, p=0.67). However, the rosuvastatin group had a higher mean LVEF at hospital discharge than the atorvastatin group (55.6% vs. 52.2%, p=0.02) after adjusting for various confounding factors using multivariable linear regression analysis. The two groups had no significant difference in peak CK-MB levels or adverse events. Based on the results, it can be concluded that in patients undergoing primary PCI, there was no significant difference in the proportion of patients achieving TIMI flow grade 3 immediately after PCI between a loading dose of rosuvastatin and atorvastatin.