We assessed the relation between platelet-to-lymphocyte ratio (PLR) on admission and contrast-induced nephropathy (CIN) in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). A total of 488 patients with NSTE-ACS who underwent urgent coronary angiography were enrolled. Levels of PLR and creatinine were measured before angiography and at 72 hours after angiography. Patients were divided into 2 groups, namely, the CIN group, 80 patients (16.3%; age 65.3 +/- 12.5years; 66.7% men) and the non-CIN group, 408 patients (83.7%; age 61.2 +/- 12.3 years; 72.5% men). Patients in the CIN group had significantly higher PLR than those in the non-CIN group (152.9 +/- 99.6 vs 120.4 +/- 66.1, P < .001). In logistic regression analysis, PLR (odds ratio [OR] 1.004, 95% confidence interval [CI] 1.001-1.007, P = .02), diabetes mellitus (OR 1.75, 95% CI 1.02-2.98, P = .03), and ST-segment depression on admission electrocardiogram (OR 1.68, 95% CI 1.00-2.81, P = .04) were independent predictors of CIN. The PLR was an independent predictor of CIN after angiography in patients with NSTE-ACS.