Objectives: To investigate whether preprocedural high-dose atorvastatin decreases the incidence of contrast-induced nephropathy (CIN) and protects the renal function after emergency percutaneous coronary intervention (PCI). Methods: Statin-naive patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing emergency PCI (n = 161) randomly received atorvastatin (80 mg, n = 78, ATOR group) or placebo [n = 83, control (CON) group] followed by long-term atorvastatin (40 mg/day). The primary end point was incidence of CIN. Results: In the ATOR group, 2.6% of the patients developed CIN versus 15.7% in the CON group (p = 0.01). In the ATOR group, postprocedural serum creatinine was significantly lower (93.4 ± 17.1 vs. 112.6 ± 23.3 µmol/l at 48 h and 84.2 ± 14.2 vs. 95.3 ± 17.7 µmol/l at 72 h, both p < 0.0001) and in the CON group, peak serum cystatin C was lower (0.51 ± 0.14 vs. 0.61 ± 0.13 mg/l, p < 0.0001). Atorvastatin pretreatment was independently associated with a decreased risk of CIN (OR 0.084, 95% CI 0.015–0.462, p = 0.004). The proportion of alanine aminotransferase >3 × upper limit of the normal value within 1 month was 3.85 versus 1.20% (ATOR vs. CON group, p = 0.57). Conclusion: Preprocedural high-dose atorvastatin prevents CIN and protects the renal function in patients with acute STEMI undergoing emergency PCI.