Contrast-induced nephropathy (CIN) has gained increasing attention in clinical practice, particularly during coronary angiography (CAG). However, some "bioequivalent" generic (GE) drugs are less effective than the innovator (IN) drug. Therefore, the aim of this study was to compare contrast media (IN drug)-induced renal dysfunction with contrast media (GE drug)-induced dysfunction. We enrolled 44 patients who underwent elective CAG or percutaneous coronary intervention (PCI) and randomly divided them into two groups that received contrast media (Iohexol, nonionic and low-osmolality contrast agent) containing either IN drug (Omnipaque) or GE drug (Iopaque). Blood and urine sampling were performed before and after (24 and 48 h) CAG or PCI. Biochemical parameters in blood (serum creatinine, cystatin C, high-sensitivity C-reactive protein, and pentraxin-3) and urine (urinary albumin/Cr and liver-type fatty acid binding protein/Cr) were measured. There were no significant differences in the biochemical parameters at baseline between the groups. In addition, there were no differences in changes in biochemical parameters in blood and urine before and after CAG or PCI between the groups, although one patient in the GE group had CIN. The degree of contrast in Iopaque-induced renal dysfunction was comparable with that in Omnipaque-induced dysfunction.