Although contrast-induced acute kidney injury (CI-AKI) has a great impact on patients' prognosis, few data exist regarding predictors of CI-AKI in patients with severe renal dysfunction who have undergone contrast angiography. Therefore, we prospectively studied 25 patients with renal dysfunction, which was defined as the estimated glomerular filtration rate (eGFR) level <45 ml/min/1.73 m(2), undergoing coronary angiography (CAG) or percutaneous coronary intervention (PCI). We performed hemodiafiltration with blood suction from the right atrium (RA-HDF). The mean level of urinary liver-type fatty acid-binding protein (L-FABP) at baseline was significantly higher in the CI-AKI group than in the non-CI-AKI group (59.8 ± 45.6 vs 13.4 ± 11.9 μg/gCr, P = 0.0003). Multivariate regression analysis demonstrated that baseline urinary L-FABP was an independent significant predictor of CI-AKI (β = 0.741, P = 0.013). Receiver-operating characteristic analysis showed that baseline urinary L-FABP exhibited 100 % sensitivity and 81.8 % specificity for predicting CI-AKI when the cutoff value was defined as 19.0 μg/gCr. Interestingly, the incidence of CI-AKI after CAG or PCI was reduced in the RA-HDF group in a comparison with 41 control patients (12 % vs 27 %) with eGFR level <45 ml/min/1.73 m(2) who underwent PCI before the introduction of RA-HDF. In conclusion, baseline L-FABP levels can be a predictor for occurrence of CI-AKI. We suggest that RA-HDF may prevent the development of CI-AKI in patients with severe renal dysfunction undergoing coronary procedures, although further large-scale prospective study is necessary to confirm our conclusions.