Abstract Objectives The purpose of this study was to determine the efficacy and safety of radial versus femoral access in women undergoing coronary angiography/intervention. Background The risk of bleeding and vascular access site complications are higher in women than in men. Methods In a pre-specified RIVAL (RadIal Vs femorAL access for coronary intervention) subgroup analysis, we compared outcomes in women (n = 1,861) and men (n = 5,160) randomized to radial versus femoral access. Results Overall, women were at higher risk of major vascular complications compared with men (4.7% vs. 1.7%; p < 0.0001). Major vascular complications were significantly reduced with radial access in women (3.1% vs. 6.1%; hazard ratio HR: 0.5; 95% confidence interval CI: 0.32 to 0.78; p = 0.002) and in men (0.7% vs. 2.8%; HR: 0.27; 95% CI: 0.17 to 0.45; p < 0.0001; interaction p = 0.092). Crossover rates were higher with radial compared with femoral access in women (11.1% vs. 1.9%; HR: 5.88; p < 0.0001) and men (6.3% vs. 1.9%; HR: 3.32; p < 0.0001; interaction p = 0.054). Percutaneous coronary intervention (PCI) success rates were similar irrespective of access site (women: HR: 1.05; p = 0.471; men: HR: 1.00; p = 0.888; interaction p = 0.674), with no differences in PCI complications. In multivariable analyses, female sex was an independent predictor of major vascular complications (HR: 2.39; 95% CI: 1.76 to 3.25; p < 0.0001). There were consistent findings for women and men, with no difference for the primary composite endpoint of death, myocardial infarction, stroke, and non–coronary artery bypass grafting bleeding (women: 3.9% vs. 5.0%; HR: 0.77; 95% CI: 0.50 to 1.19; men: 3.54% vs. 3.5%; HR: 1.00; 95% CI: 0.75 to −1.34; interaction p = 0.325). Conclusions Women undergoing coronary angiography and PCI have a higher risk of vascular access site complications compared with men, and radial access is an effective method to reduce these complications.