Background: Use of the transradial approach (TRA) in percutaneous coronary intervention (PCI) has increased in recent years. TRA has a lower mortality rate than the transfemoral approach (TFA) in patients with acute coronary syndrome. Comparative studies have systematically excluded patients with cardiogenic shock (CS). Methods: We performed a prospective, observational registry study of consecutive patients undergoing emergent revascularization between February 2007 and January 2012. An analysis of the clinical evolution of patients with CS during hospitalization was performed. Results: Of 1,400 emergency procedures, 122 had CS, of which 80 underwent PCI by TRA (65.6%) and 42 underwent PCI by TFA (34.3%). The main reason for choosing TFA was the absence of radial pulse (54.9%). Mortality (64.3% vs 32.5%, P =.001), serious access site complications (11.9% vs 2.5%, P =.03), access site complications requiring blood transfusion (7.1% vs 0%, P =.04), and major adverse cardiac events (death, infarction, stroke, serious bleeding, and postanoxic encephalopathy) (73.8% vs 43.8%, P =.001) were greater in patients treated by TFA. In the multivariate analysis, TRA was a predictor of mortality (odds ratio [OR] 0.39 [0.15-0.97]); other predictive factors were age ≥75 years (3.47 [1.35-8.92]), previous treatment with diuretics (3.67 [1.21-11.12]), and success of the procedure (0.07 [0.02-0.24]). Conclusions: Transradial approach for PCI is possible and safe in up to two-thirds of patients with CS. Absence of radial pulse was the main factor preventing use of TRA. In multivariate analysis, TRA was associated with a lower risk of mortality. © 2013 Mosby, Inc. All rights reserved.