Introduction: The risk of contrast-induced nephropathy (CIN) as a common and important complication of coronary procedures may be influenced by the vascular access site. We compared the risks of CIN in diagnostic or interventional coronary management between patients treated via the transradial access (TRA) and those treated via the transfemoral access (TFA).<br /> Methods: Patients undergoing invasive coronary catheterization or percutaneous coronary intervention (PCI) were enrolled. We excluded patients with congenital or structural heart disease and those with end-stage renal disease on dialysis. Based on the vascular access site used for invasive coronary catheterization, the patients were divided into 2 study groups: the TFA and the TRA. CIN was defined as an absolute (≥0.5 mg/dL) or relative (>25%) increase in the baseline serum creatinine level within 48 hours following cardiac catheterization or PCI.<br /> Results: Overall, 410 patients (mean age = 61.3 ± 10.8 years) underwent diagnostic or interventional coronary management: 258 were treated via the TFA approach and 152 via the TRA approach. The patients treated via the TFA had a significantly higher incidence of postprocedural CIN (15.1% vs 6.6%; P = 0.01). The multivariate analysis showed that the TFA was the independent predictor of CIN (OR: 2.37, 95% CI: 1.11 to 5.10, and P = 0.027). Moreover, the BARC (Bleeding Academic Research Consortium) and Mehran scores were the other independent predictors of CIN in our study.<br /> Conclusion: The risk of CIN was lower with the TRA, and the TFA was the independent predictor of CIN after the diagnostic or interventional coronary management.